The 100 most-cited articles in Physical review. D/Physical review. D., 2020

We report the observation of gravitational waves from a binary-black-hole coalescence during the first two weeks of LIGO’s and Virgo’s third observing run. The signal was recorded on April 12, 2019 at 05∶30∶44 UTC with a network signal-to-noise ratio of 19. The binary is different from observations during the first two observing runs most notably due to its asymmetric masses: a ∼ 30 M ⊙ black hole merged with a ∼ 8 M ⊙ black hole companion. The more massive black hole rotated with a dimensionless spin magnitude between 0.22 and 0.60 (90% probability). Asymmetric systems are predicted to emit gravitational waves with stronger contributions from higher multipoles, and indeed we find strong evidence for gravitational radiation beyond the leading quadrupolar order in the observed signal. A suite of tests performed on GW190412 indicates consistency with Einstein’s general theory of relativity. While the mass ratio of this system differs from all previous detections, we show that it is consistent with the population model of stellar binary black holes inferred from the first two observing…

Measurements of the Hubble constant and, more generally, measurements of the expansion rate and distances over the interval $0<z<1$ appear to be inconsistent with the predictions of the standard cosmological model ($\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$) given observations of cosmic microwave background temperature and polarization anisotropies. Here we consider a variety of types of departures from $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ that could, in principle, restore concordance among these datasets, and we explain why we find almost all of them unlikely to be successful. We single out the set of solutions that increases the expansion rate in the decade of scale factor expansion just prior to recombination as the least unlikely. These solutions are themselves tightly constrained by their impact on photon diffusion and on the gravitational driving of acoustic oscillations of the modes that begin oscillating during this epoch---modes that project on to angular scales that are very well measured. We point out that a general feature of such solutions is a residual to fits…

Following updates in the compilation of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\text{hadrons}$ data, this work presents reevaluations of the hadronic vacuum polarization contributions to the anomalous magnetic moments of the electron (${a}_{e}$), muon (${a}_{\ensuremath{\mu}}$) and tau lepton (${a}_{\ensuremath{\tau}}$), to the ground-state hyperfine splitting of muonium and also updates the hadronic contributions to the running of the QED coupling at the mass scale of the $Z$ boson, $\ensuremath{\alpha}({M}_{Z}^{2})$. Combining the results for the hadronic vacuum polarization contributions with recent updates for the hadronic light-by-light corrections, the electromagnetic and the weak contributions, the deviation between the measured value of ${a}_{\ensuremath{\mu}}$ and its Standard Model prediction amounts to $\mathrm{\ensuremath{\Delta}}{a}_{\ensuremath{\mu}}=(28.02\ifmmode\pm\else\textpm\fi{}7.37)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$, corresponding to a muon $g\ensuremath{-}2$ discrepancy of $3.8\ensuremath{\sigma}$.

The universal character of the gravitational interaction provided by the equivalence principle motivates a geometrical description of gravity. The standard formulation of general relativity \`a la Einstein attributes gravity to the spacetime curvature, to which we have grown accustomed. However, this perception has masked the fact that two alternative, though equivalent, formulations of general relativity in flat spacetimes exist, where gravity can be fully ascribed either to torsion or to nonmetricity. The latter allows a simpler geometrical formulation of general relativity that is oblivious to the affine spacetime structure. Generalizations along this line permit us to generate teleparallel and symmetric teleparallel theories of gravity with exceptional properties. In this work we explore modified gravity theories based on nonlinear extensions of the nonmetricity scalar. After presenting some general properties and briefly studying some interesting background cosmologies (including accelerating solutions with relevance for inflation and dark energy), we analyze the behavior of…

The strong discrepancy between local and early-time (inverse distance ladder) estimates of the Hubble constant ${H}_{0}$ could be pointing towards new physics beyond the concordance $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model. Several attempts to address this tension through new physics rely on extended cosmological models, featuring extra free parameters beyond the six $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ parameters. However, marginalizing over additional parameters has the effect of broadening the uncertainties on the inferred parameters (including ${H}_{0}$), and it is often the case that within these models the ${H}_{0}$ tension is addressed due to larger uncertainties rather than a genuine shift in the central value of ${H}_{0}$. In this paper I consider an alternative viewpoint: what happens if a physical theory is able to fix the extra parameters to a specific set of nonstandard values? In this case, the degrees of freedom of the model are reduced with respect to the standard case where the extra parameters are free to vary. Focusing on the dark energy equation…

We report results from searches for new physics with low-energy electronic recoil data recorded with the XENON1T detector.With an exposure of 0.65 tonne-years and an unprecedentedly low background rate of 76 Æ 2 stat events=ðtonne × year × keVÞ between 1 and 30 keV, the data enable one of the most sensitive searches for solar axions, an enhanced neutrino magnetic moment using solar neutrinos, and bosonic dark matter.An excess over known backgrounds is observed at low energies and most prominent between 2 and 3 keV.The solar axion model has a 3.4σ significance, and a three-dimensional 90% confidence surface is reported for axion couplings to electrons, photons, and nucleons.This surface is inscribed in the cuboid defined by g ae < 3.8 × 10 -12 , g ae g eff an < 4.8 × 10 -18 , and g ae g aγ < 7.7 × 10 -22 GeV -1 , and excludes eitherThe neutrino magnetic moment signal is similarly favored over background at 3.2σ, and a confidence interval of μ ν ∈ ð1.4; 2.9Þ × 10 -11 μ B (90% C.L.) is reported.Both results are in strong tension with stellar constraints.The excess can also be explained…

Combined measurements of Higgs boson production cross sections and branching fractions are presented. The combination is based on the analyses of the Higgs boson decay modes $H\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$, $Z{Z}^{*}$, $W{W}^{*}$, $\ensuremath{\tau}\ensuremath{\tau}$, $b\overline{b}$, $\ensuremath{\mu}\ensuremath{\mu}$, searches for decays into invisible final states, and on measurements of off-shell Higgs boson production. Up to $79.8\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of proton--proton collision data collected at $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$ with the ATLAS detector are used. Results are presented for the gluon--gluon fusion and vector-boson fusion processes, and for associated production with vector bosons or top-quarks. The global signal strength is determined to be $\ensuremath{\mu}=1.1{1}_{\ensuremath{-}0.08}^{+0.09}$. The combined measurement yields an observed (expected) significance for the vector-boson fusion production process of $6.5\ensuremath{\sigma}$ ($5.3\ensuremath{\sigma}$). Measurements in kinematic…

How to represent a jet is at the core of machine learning on jet physics. Inspired by the notion of point clouds, we propose a new approach that considers a jet as an unordered set of its constituent particles, effectively a ``particle cloud.'' Such a particle cloud representation of jets is efficient in incorporating raw information of jets and also explicitly respects the permutation symmetry. Based on the particle cloud representation, we propose ParticleNet, a customized neural network architecture using Dynamic Graph Convolutional Neural Network for jet tagging problems. The ParticleNet architecture achieves state-of-the-art performance on two representative jet tagging benchmarks and is improved significantly over existing methods.

On April 1st, 2019, the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO), joined by the Advanced Virgo detector, began the third observing run, a year-long dedicated search for gravitational radiation. The LIGO detectors have achieved a higher duty cycle and greater sensitivity to gravitational waves than ever before, with LIGO Hanford achieving angle-averaged sensitivity to binary neutron star coalescences to a distance of 111 Mpc, and LIGO Livingston to 134 Mpc with duty factors of 74.6% and 77.0% respectively. The improvement in sensitivity and stability is a result of several upgrades to the detectors, including doubled intracavity power, the addition of an in-vacuum optical parametric oscillator for squeezed-light injection, replacement of core optics and end reaction masses, and installation of acoustic mode dampers. This paper explores the purposes behind these upgrades, and explains to the best of our knowledge the noise currently limiting the sensitivity of each detector.

We explore whether nonstandard dark sector physics might be required to solve the existing cosmological tensions. The properties we consider in combination are (a) an interaction between the dark matter and dark energy components and (b) a dark energy equation of state $w$ different from that of the canonical cosmological constant $w=\ensuremath{-}1$. In principle, these two parameters are independent. In practice, to avoid early-time, superhorizon instabilities, their allowed parameter spaces are correlated. Moreover, a clear degeneracy exists between these two parameters in the case of cosmic microwave background (CMB) data. We analyze three classes of extended interacting dark energy models in light of the 2019 Planck CMB results and Cepheid-calibrated local distance ladder ${H}_{0}$ measurements of Riess et al. (R19), as well as recent baryon acoustic oscillation (BAO) and type Ia supernovae (SNeIa) distance data. We find that in quintessence coupled dark energy models, where $w>\ensuremath{-}1$, the evidence for a nonzero coupling between the two dark sectors can surpass the…

We discuss the phase structure of QCD for ${N}_{f}=2$ and ${N}_{f}=2+1$ dynamical quark flavors at finite temperature and baryon chemical potential. It emerges dynamically from the underlying fundamental interactions between quarks and gluons in our work. To this end, starting from the perturbative high-energy regime, we systematically integrate out quantum fluctuations toward low energies by using the functional renormalization group. By dynamically hadronizing the dominant interaction channels responsible for the formation of light mesons and quark condensates, we are able to extract the phase diagram for ${\ensuremath{\mu}}_{B}/T\ensuremath{\lesssim}6$. We find a critical endpoint at $({T}_{\mathrm{CEP}},{\ensuremath{\mu}}_{{B}_{\mathrm{CEP}}})=(107,635)\text{ }\text{ }\mathrm{MeV}$. The curvature of the phase boundary at small chemical potential is $\ensuremath{\kappa}=0.0142(2)$, computed from the renormalized light chiral condensate ${\mathrm{\ensuremath{\Delta}}}_{l,R}$. Furthermore, we find indications for an inhomogeneous regime in the vicinity and above the chiral…

We report the detection of new binary black hole merger events in the publicly available data from the second observing run of Advanced LIGO and Advanced Virgo (O2). The mergers were discovered using the new search pipeline described in Venumadhav et al. [Phys. Rev. D 100, 023011 (2019)] and are above the detection thresholds as defined in Abbott et al. (LIGO Scientific and Virgo Collaborations) [Phys. Rev. X 9, 031040 (2019).]. Three of the mergers (GW170121, GW170304, GW170727) have inferred probabilities of being of astrophysical origin ${p}_{\text{astro}}>0.98$. The remaining three (GW170425, GW170202, GW170403) are less certain, with ${p}_{\text{astro}}$ ranging from 0.5 to 0.8. The newly found mergers largely share the statistical properties of previously reported events, with the exception of GW170403, the least secure event, which has a highly negative effective spin parameter ${\ensuremath{\chi}}_{\mathrm{eff}}$. The most secure new event, GW170121 (${p}_{\text{astro}}>0.99$), is also notable due to its inferred negative value of ${\ensuremath{\chi}}_{\mathrm{eff}}$, which…

Different measurements of the Hubble constant are somewhat in tension. Here, the authors show that a simple effective theory of neutrino self-interactions can lead to a significantly different cosmology. This resolves the Hubble issue while also suggesting an extra neutrino species that could relate to experimental neutrino anomalies. Their results suggest interesting deviations from the standard cosmology may be viable.

We present a detailed investigation of a subdominant oscillating scalar field [``early dark energy'' (EDE)] in the context of resolving the Hubble tension. Consistent with earlier work, but without relying on fluid approximations, we find that a scalar field frozen due to Hubble friction until ${\mathrm{log}}_{10}({z}_{c})\ensuremath{\sim}3.5$, reaching ${\ensuremath{\rho}}_{\mathrm{EDE}}({z}_{c})/{\ensuremath{\rho}}_{\mathrm{tot}}\ensuremath{\sim}10%$ and diluting faster than matter afterwards, can bring cosmic microwave background (CMB), baryonic acoustic oscillations, supernovae luminosity distances, and the late-time estimate of the Hubble constant from the SH0ES Collaboration into agreement. A scalar field potential that scales as $V(\ensuremath{\phi})\ensuremath{\propto}{\ensuremath{\phi}}^{2n}$ with $2\ensuremath{\lesssim}n\ensuremath{\lesssim}3.4$ around the minimum is preferred at the 68% confidence level, and the Planck polarization places additional constraints on the dynamics of perturbations in the scalar field. In particular, the data prefer a potential that flattens…

Observations of neutron stars, whether in binaries or in isolation, provide information about the internal structure of the most extreme material objects in the Universe. In this work, we combine information from recent observations to place joint constraints on the properties of neutron star matter. We use (i) lower limits on the maximum mass of neutron stars obtained through radio observations of heavy pulsars, (ii) constraints on tidal properties inferred through the gravitational waves neutron star binaries emit as they coalesce, and (iii) information about neutron stars' masses and radii obtained through X-ray emission from surface hot spots. In order to combine information from such distinct messengers while avoiding the kind of modeling systematics intrinsic to parametric inference schemes, we employ a nonparametric representation of the neutron-star equation of state based on Gaussian processes conditioned on nuclear theory models. We find that existing astronomical observations imply ${R}_{1.4}=12.3{2}_{\ensuremath{-}1.47}^{+1.09}\text{ }\text{ }\mathrm{km}$ for the radius…

As gravitational-wave detectors become more sensitive and broaden their frequency bandwidth, we will access a greater variety of signals emitted by compact binary systems, shedding light on their astrophysical origin and environment. A key physical effect that can distinguish among different formation scenarios is the misalignment of the spins with the orbital angular momentum, causing the spins and the binary's orbital plane to precess. To accurately model such precessing signals, especially when masses and spins vary in the wide astrophysical range, it is crucial to include multipoles beyond the dominant quadrupole. Here, we develop the first multipolar precessing waveform model in the effective-one-body (EOB) formalism for the entire coalescence stage (i.e., inspiral, merger and ringdown) of binary black holes: SEOBNRv4PHM. In the nonprecessing limit, the model reduces to SEOBNRv4HM, which was calibrated to numerical-relativity (NR) simulations, and waveforms from black-hole perturbation theory. We validate SEOBNRv4PHM by comparing it to the public catalog of 1405 precessing NR…

The authors provide a thorough study of a popular scenario (early dark energy EDE) to alleviate the tension in the measurements of the Hubble constant ${H}_{0}$, which either rely on early Universe probes and the cosmological standard model ($\mathrm{\ensuremath{\Lambda}}$CDM) or on late Universe probes through direct, local distant measurements. The authors show that the inclusion of numerous large-scale structure data is in conflict with the parameter space that lifts the ${H}_{0}$ tension and severely limits the existence of EDE and, thus, makes it very unlikely to resolve the tension.

We present the imrphenomxhm frequency domain phenomenological waveform model for the inspiral, merger, and ringdown of quasicircular nonprecessing black hole binaries. The model extends the imrphenomxas waveform model [G. Pratten, S. Husa, C. Garc\'{\i}a-Quir\'os, M. Colleoni, A. Ramos-Buades, H. Estell\'es, and R. Jaume, preceding paper, Phys. Rev. D 102, 064001 (2020)], which describes the dominant quadrupole modes $\ensuremath{\ell}=|m|=2$, to the harmonics $(\ensuremath{\ell},|m|)=(2,1),(3,3),(3,2),(4,4)$, and includes mode mixing effects for the (3,2) spherical harmonic. imrphenomxhm is calibrated against hybrid waveforms, which match an inspiral phase described by the effective-one-body model and post-Newtonian amplitudes for the subdominant harmonics to numerical relativity waveforms and numerical solutions to the perturbative Teukolsky equation for large mass ratios up to 1000.

LUX-ZEPLIN (LZ) is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with weakly interacting massive particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6-tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above $1.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}48}\text{ }\text{ }{\mathrm{cm}}^{2}$ for a $40\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ mass WIMP. Additionally, a $5\ensuremath{\sigma}$ discovery potential is projected, reaching cross sections below the exclusion limits of recent experiments. For spin-dependent WIMP-neutron(-proton) scattering, a…

We leverage recent breakthroughs in neural density estimation to propose a new unsupervised ANOmaly detection with Density Estimation (ANODE) technique. By estimating the conditional probability density of the data in a signal region and in sidebands, and interpolating the latter into the signal region, a fully data-driven likelihood ratio of data versus background can be constructed. This likelihood ratio is broadly sensitive to overdensities in the data that could be due to localized anomalies. In addition, a unique potential benefit of the ANODE method is that the background can be directly estimated using the learned densities. Finally, ANODE is robust against systematic differences between signal region and sidebands, giving it broader applicability than other methods. We demonstrate the power of this new approach using the LHC Olympics 2020 R dataset. We show how ANODE can enhance the significance of a dijet bump hunt by up to a factor of 7 with a 10% accuracy on the background prediction. While the LHC is used as the recurring example, the methods developed here have a much…

In this paper we present imrphenomxas, a thorough overhaul of the imrphenomd [S. Husa et al., Phys. Rev. D 93, 044006 (2016); S. Khan et al., Phys. Rev. D 93, 044007 (2016)] waveform model, which describes the dominant $l=2$, $|m|=2$ spherical harmonic mode of nonprecessing coalescing black holes in terms of piecewise closed form expressions in the frequency domain. Improvements include in particular the accurate treatment of unequal spin effects, and the inclusion of extreme mass ratio waveforms. imrphenomd has previously been extended to approximately include spin precession [M. Hannam et al., Phys. Rev. Lett. 113, 151101 (2014)] and subdominant spherical harmonics [L. London et al., Phys. Rev. Lett. 120, 161102 (2018)], and with its extensions it has become a standard tool in gravitational wave parameter estimation. Improved extensions of imrphenomxas are discussed in companion papers [C. Garc\'{\i}a-Quir\'os et al., Phys. Rev. D 102, 064002 (2020); G. Pratten et al., arXiv:2004.06503].

We perform a joint analysis of the counts and weak lensing signal of redMaPPer clusters selected from the Dark Energy Survey (DES) Year 1 dataset. Our analysis uses the same shear and source photometric redshifts estimates as were used in the DES combined probes analysis. Our analysis results in surprisingly low values for ${S}_{8}={\ensuremath{\sigma}}_{8}({\mathrm{\ensuremath{\Omega}}}_{\mathrm{m}}/0.3{)}^{0.5}=0.65\ifmmode\pm\else\textpm\fi{}0.04$, driven by a low matter density parameter, ${\mathrm{\ensuremath{\Omega}}}_{\mathrm{m}}=\phantom{\rule{0ex}{0ex}}0.17{9}_{\ensuremath{-}0.038}^{+0.031}$, with ${\ensuremath{\sigma}}_{8}\ensuremath{-}{\mathrm{\ensuremath{\Omega}}}_{\mathrm{m}}$ posteriors in $2.4\ensuremath{\sigma}$ tension with the DES Y1 3x2pt results, and in $5.6\ensuremath{\sigma}$ with the Planck CMB analysis. These results include the impact of post-unblinding changes to the analysis, which did not improve the level of consistency with other data sets compared to the results obtained at the unblinding. The fact that multiple cosmological probes (supernovae, baryon…

We present a new version of the hadron interaction event generator sibyll. While the core ideas of the model have been preserved, the new version handles the production of baryon pairs and leading particles in a new way. In addition, production of charmed hadrons is included. Updates to the model are informed by high-precision measurements of the total and inelastic cross sections with the forward detectors at the LHC that constrain the extrapolation to ultrahigh energy. Minimum-bias measurements of particle spectra and multiplicities support the tuning of fragmentation parameters. This paper demonstrates the impact of these changes on air-shower observables such as ${X}_{\mathrm{max}}$ and ${N}_{\ensuremath{\mu}}$, drawing comparisons with other contemporary cosmic-ray interaction models.

All nonlinear extensions of the source-free Maxwell equations preserving both $SO(2)$ electromagnetic duality invariance and conformal invariance are found, and shown to be limits of a one-parameter generalization of Born-Infeld electrodynamics. The strong-field limit is the same as that found by Bialynicki-Birula from Born-Infeld theory but the weak-field limit is a new one-parameter extension of Maxwell electrodynamics, which is interacting but admits exact light-velocity plane-wave solutions of arbitrary polarization. Small-amplitude waves on a constant uniform electromagnetic background exhibit birefringence, but one polarization mode remains lightlike.

We formulate Barrow holographic dark energy, by applying the usual holographic principle at a cosmological framework, but using the Barrow entropy instead of the standard Bekenstein-Hawking one. The former is an extended black-hole entropy that arises due to quantum-gravitational effects which deform the black-hole surface by giving it an intricate, fractal form. We extract a simple differential equation for the evolution of the dark-energy density parameter, which possesses standard holographic dark energy as a limiting subcase, and we show that the scenario can describe the thermal history of the universe, with the sequence of matter and dark-energy eras. Additionally, the new Barrow exponent $\mathrm{\ensuremath{\Delta}}$ significantly affects the dark-energy equation of state, and according to its value it can lead it to lie in the quintessence regime, in the phantom regime, or experience the phantom-divide crossing during the evolution.

We introduce a potentially powerful new method of searching for new physics at the LHC, using autoencoders and unsupervised deep learning. The key idea of the autoencoder is that it learns to map ``normal'' events back to themselves, but fails to reconstruct ``anomalous'' events that it has never encountered before. The reconstruction error can then be used as an anomaly threshold. We demonstrate the effectiveness of this idea using QCD jets as background and boosted top jets and R-parity violating (RPV) gluino jets as signal. We show that a deep autoencoder can significantly improve signal over background when trained on backgrounds only, or even directly on data which contain a small admixture of signal. Finally, we examine the correlation of the autoencoders with jet mass and show how the jet mass distribution can be stable against cuts in reconstruction loss. This may be important for estimating QCD backgrounds from data. As a test case, we show how one could plausibly discover 400 GeV RPV gluinos using an autoencoder combined with a bump hunt in jet mass. This opens up the…

The International Gamma-Ray Astrophysics Laboratory ($INTEGRAL$) satellite has yielded unprecedented measurements of the soft gamma-ray spectrum of our Galaxy. Here we use those measurements to set constraints on dark matter (DM) that decays or annihilates into photons with energies $E\ensuremath{\approx}0.02--2\text{ }\text{ }\mathrm{MeV}$. First, we revisit the constraints on particle DM that decays or annihilates to photon pairs. In particular, for decaying DM, we find that previous limits were overstated by roughly an order of magnitude. Our new, conservative analysis finds that the DM lifetime must satisfy $\ensuremath{\tau}\ensuremath{\gtrsim}5\ifmmode\times\else\texttimes\fi{}{10}^{26}\text{ }\mathrm{s}\ifmmode\times\else\texttimes\fi{}({m}_{\ensuremath{\chi}}/\mathrm{MeV}{)}^{\ensuremath{-}1}$ for DM masses ${m}_{\ensuremath{\chi}}=0.054--3.6\text{ }\text{ }\mathrm{MeV}$. For MeV-scale DM that annihilates into photons $INTEGRAL$ sets the strongest constraints to date. Second, we target ultralight primordial black holes (PBHs) through their Hawking radiation. This makes them…

A complete theory of gravity impels us to go beyond Einstein's general relativity. One promising approach lies in a new class of teleparallel theory of gravity named $f(Q)$, where the nonmetricity $Q$ is responsible for the gravitational interaction. The important roles any of these alternative theories should obey are the energy condition constraints. Such constraints establish the compatibility of a given theory with the causal and geodesic structure of space-time. In this work, we present a complete test of energy conditions for $f(Q)$ gravity models. The energy conditions allowed us to fix our free parameters, restricting the families of $f(Q)$ models compatible with the accelerated expansion our Universe passes through. Our results strengthen the viability of $f(Q)$ theory, leading us close to the dawn of a complete theory for gravitation.

A dynamical quantum simulation of SU(2) non-Abelian gauge field theory on a digital quantum computer is presented. This was enabled on current quantum hardware by introducing a mapping of the field onto a register of qubits that utilizes local gauge symmetry while preserving local constraints on the fields, reducing the dimensionality of the calculation. Controlled plaquette operators and gauge-variant completions in the unphysical part of the Hilbert space were designed and used to implement time evolution. The new techniques developed in this work generalize to quantum simulations of higher dimensional gauge field theories.

In this paper, we argue and show numerically that the threshold to form primordial black holes from an initial spherically symmetric perturbation is, to an excellent approximation, universal, whenever given in terms of the compaction function averaged over a sphere of radius ${r}_{m}$, where ${r}_{m}$ is the scale on which the compaction function is maximum. This can be understood as the requirement that, for a black hole to form, each shell of the averaged compaction function should have an amplitude exceeding the so-called Harada-Yoo-Kohri limit. For a radiation dominated universe we argued, supported by the numerical simulations, that this limit is ${\ensuremath{\delta}}_{c}=0.40$, which is slightly below the one quoted in the literature. Additionally, we show that the profile dependence of the threshold for the compaction function is only sensitive to its curvature at the maximum. We use these results to provide an analytic formula for the threshold amplitude of the compaction function at its maximum in terms of the normalized compaction function curvature at ${r}_{m}$.

An axion-like field comprising $\ensuremath{\sim}10%$ of the energy density of the Universe near matter-radiation equality is a candidate to resolve the Hubble tension; this is the ``early dark energy'' (EDE) model. However, as shown in Hill et al., the model fails to simultaneously resolve the Hubble tension and maintain a good fit to both cosmic microwave background (CMB) and large-scale structure (LSS) data. Here, we use redshift-space galaxy clustering data to sharpen constraints on the EDE model. We perform the first EDE analysis using the full-shape power spectrum likelihood from the Baryon Oscillation Spectroscopic Survey (BOSS), based on the effective field theory (EFT) of LSS. The inclusion of this likelihood in the EDE analysis yields a 25% tighter error bar on ${H}_{0}$ compared to primary CMB data alone, yielding ${H}_{0}=68.5{4}_{\ensuremath{-}0.95}^{+0.52}\text{ }\text{ }\mathrm{km}/\mathrm{s}/\mathrm{Mpc}$ (68% C.L.). In addition, we constrain the maximum fractional energy density contribution of the EDE to ${f}_{\mathrm{EDE}}<0.072$ (95% C.L.). We explicitly…

The nonminimal coupling of the nonzero vacuum expectation value of the self-interacting antisymmetric Kalb-Ramond field with gravity leads to a power-law hairy black hole having a parameter $s$, which encompasses the Reissner-Nordstrom black hole ($s=1$). We obtain the axially symmetric counterpart of this hairy solution, namely, the rotating Kalb-Ramond black hole, which encompasses, as special cases, Kerr ($s=0$) and Kerr-Newman ($s=1$) black holes. Interestingly, for a set of parameters ($M$, $a$, and $\mathrm{\ensuremath{\Gamma}}$), there exists an extremal value of the Kalb-Ramond parameter ($s={s}_{e}$), which corresponds to an extremal black hole with degenerate horizons, while for $s<{s}_{e}$, it describes a nonextremal black hole with Cauchy and event horizons, and no black hole for $s>{s}_{e}$. We find that the extremal value ${s}_{e}$ is also influenced by these parameters. The black hole shadow size decreases monotonically and the shape gets more distorted with an increasing $s$; in turn, shadows of rotating Kalb-Ramond black holes are smaller and more distorted than the…

Anti-de Sitter (AdS) vacua, being theoretically important, might have an unexpected impact on the observable Universe. We find that in early dark energy (EDE) scenarios the existence of AdS vacua around recombination can effectively lift the CMB-inferred ${H}_{0}$ value. As an example, we study a phenomenological EDE model with an AdS phase starting at the redshift $z\ensuremath{\sim}2000$ and ending shortly after recombination (hereafter the universe will settle down in a $\mathrm{\ensuremath{\Lambda}}>0$ phase until now), and obtain a best-fit ${H}_{0}=72.74\text{ }\text{ }\mathrm{km}/\mathrm{s}/\mathrm{Mpc}$ without degrading the CMB fit compared with the standard $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model.

We propose a new test of strong-field general relativity (GR) based on the universal interferometric signature of the black hole photon ring. The photon ring is a narrow ring-shaped feature, predicted by GR but not yet observed, that appears on images of sources near a black hole. It is caused by extreme bending of light within a few Schwarzschild radii of the event horizon and provides a direct probe of the unstable bound photon orbits of the Kerr geometry. We show that the precise shape of the observable photon ring is remarkably insensitive to the astronomical source profile and can therefore be used as a stringent test of GR. We forecast that a tailored space-based interferometry experiment targeting M87* could test the Kerr nature of the source to the sub-subpercent level.

New early dark energy (NEDE) is a component of vacuum energy at the electron volt scale, which decays in a first-order phase transition shortly before recombination [F. Niedermann and M. S. Sloth, New early dark energy]. The NEDE component has the potential to resolve the tension between recent local measurements of the expansion rate of the Universe using supernovae (SN) data and the expansion rate inferred from the early Universe through measurements of the cosmic microwave background (CMB) when assuming $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$. We discuss in depth the two-scalar field model of the NEDE phase transition including the process of bubble percolation, collision, and coalescence. We also estimate the gravitational wave signal produced during the collision phase and argue that it can be searched for using pulsar timing arrays. In a second step, we construct an effective cosmological model, which describes the phase transition as an instantaneous process, and derive the covariant equations that match perturbations across the transition surface. Fitting the…

Interpreting horizon-scale observations of astrophysical black holes demands a general understanding of null geodesics in the Kerr spacetime. These may be divided into two classes: ``direct'' rays that primarily determine the observational appearance of a given source, and highly bent rays that produce a nested sequence of exponentially demagnified images of the main emission: the so-called ``photon ring.'' We develop heuristics that characterize the direct rays and study the highly bent geodesics analytically. We define three critical parameters $\ensuremath{\gamma}$, $\ensuremath{\delta}$, and $\ensuremath{\tau}$ that respectively control the demagnification, rotation, and time delay of successive images of the source, thereby providing an analytic theory of the photon ring. These observable parameters encode universal effects of general relativity, independent of the details of the emitting matter.

We study the implications of the recently proposed Trans-Planckian censorship conjecture (TCC) for early Universe cosmology and in particular inflationary cosmology. The TCC leads to the conclusion that if we want inflationary cosmology to provide a successful scenario for cosmological structure formation, the energy scale of inflation has to be lower than ${10}^{9}\text{ }\text{ }\mathrm{GeV}$. Demanding the correct amplitude of the cosmological perturbations then forces the generalized slow-roll parameter $\ensuremath{\epsilon}$ of the model to be very small ($<{10}^{\ensuremath{-}31}$). This leads to the prediction of a negligible amplitude of primordial gravitational waves. For slow-roll inflation models, it also leads to severe fine-tuning of initial conditions.

We investigate the conditions for the (in)stability of the isotropic pressure condition in collapsing spherically symmetric, dissipative fluid distributions. It is found that dissipative fluxes, and/or energy density inhomogeneities and/or the appearance of shear in the fluid flow, force any initially isotropic configuration to abandon such a condition, generating anisotropy in the pressure. To reinforce this conclusion we also present some arguments concerning the axially symmetric case. The consequences of our results are analyzed.

In an amplitude analysis of the ${B}^{+}\ensuremath{\rightarrow}{D}^{+}\phantom{\rule{0}{0ex}}{D}^{\ensuremath{-}}\phantom{\rule{0}{0ex}}{K}^{+}$ decay, the LHCb Collaboration finds evidence for new spin-0 and spin-1 exotic open-charm and open_strangeness resonances in the ${D}^{\ensuremath{-}}\phantom{\rule{0}{0ex}}{K}^{+}$ channel with masses around 2.9 GeV. These resonances must contain at least four quarks, namely an up and down quark besides the charm and strange antiquarks.

Cosmography is an ideal tool to investigate the cosmic expansion history of the Universe in a model-independent way. The equations of motion in modified theories of gravity are usually very complicated; cosmography may select practical models without imposing arbitrary choices a priori. We use the model-independent way to derive $f(z)$ and its derivatives up to fourth order in terms of measurable cosmographic parameters. We then fit those functions into the luminosity distance directly. We perform the MCMC analysis by considering three different sets of cosmographic functions. Using the largest supernovae Ia Pantheon sample, we derive the constraints on the Hubble constant ${H}_{0}$ and the cosmographic functions, and find that the former two terms in Taylor expansion of luminosity distance work dominantly in $f(Q)$ gravity.

This paper presents results of searches for the electroweak production of supersymmetric particles in models with compressed mass spectra. The searches use $139\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$ proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider. Events with missing transverse momentum and two same-flavor, oppositely charged, low-transverse-momentum leptons are selected, and are further categorized by the presence of hadronic activity from initial-state radiation or a topology compatible with vector-boson fusion processes. The data are found to be consistent with predictions from the Standard Model. The results are interpreted using simplified models of $R$-parity-conserving supersymmetry in which the lightest supersymmetric partner is a neutralino with a mass similar to the lightest chargino, the second-to-lightest neutralino, or the slepton. Lower limits on the masses of charginos in different simplified models range from 193 to 240 GeV for moderate mass splittings, and extend down…

We propose a regularization procedure for the novel Einstein-Gauss-Bonnet theory of gravity, which produces a set of field equations that can be written in closed form in four dimensions. Our method consists of introducing a counterterm into the action, and does not rely on the embedding or compactification of any higher-dimensional spaces. This counterterm is sufficient to cancel the divergence in the action that would otherwise occur, and exactly reproduces the trace of the field equations of the original formulation of the theory. All other field equations display an extra scalar gravitational degree of freedom in the gravitational sector, in keeping with the requirements of Lovelock's theorem. We discuss issues concerning the equivalence between our new regularized theory and the original.

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We present a new open-source code that calculates one-loop power spectra and cross spectra for matter fields and biased tracers in real and redshift space. These spectra incorporate all ingredients required for a direct application to data: nonlinear bias and redshift-space distortions, infrared resummation, counterterms, and the Alcock-Paczynski effect. Our code is based on the Boltzmann solver class and inherits its advantageous properties: user friendliness, ease of modification, high speed, and simple interface with other software. We present detailed descriptions of the theoretical model, the code structure, approximations, and accuracy tests. A typical end-to-end run for one cosmology takes 0.3 seconds, which is sufficient for Markov chain Monte Carlo parameter extraction. As an example, we apply the code to the Baryon Oscillation Spectroscopic Survey (BOSS) data and infer cosmological parameters from the shape of the galaxy power spectrum.

The discrepancy between the Standard Model theory and experimental measurement of the muon magnetic moment anomaly, ${a}_{\ensuremath{\mu}}=({g}_{\ensuremath{\mu}}\ensuremath{-}2)/2$, is connected to precision electroweak (EW) predictions via their common dependence on hadronic vacuum polarization effects. The same data for the total ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\text{hadrons}$ cross section, ${\ensuremath{\sigma}}_{\text{had}}(s)$, are used as input into dispersion relations to estimate the hadronic vacuum polarization contributions, ${a}_{\ensuremath{\mu}}^{\text{had},\mathrm{VP}}$, as well as the five-flavor hadronic contribution to the running QED coupling at the $Z$-pole, $\mathrm{\ensuremath{\Delta}}{\ensuremath{\alpha}}_{\text{had}}^{(5)}({M}_{Z}^{2})$, which enters natural relations and global EW fits. The EW fit prediction of $\mathrm{\ensuremath{\Delta}}{\ensuremath{\alpha}}_{\text{had}}^{(5)}({M}_{Z}^{2})=0.02722(41)$ agrees well with $\mathrm{\ensuremath{\Delta}}{\ensuremath{\alpha}}_{\text{had}}^{(5)}({M}_{Z}^{2})=0.02761(11)$ obtained from the…

New structural properties of post-Minkowskian (PM) gravity are derived, notably within its effective one body (EOB) formulation. Our results concern both the mass dependence, and the high-energy behavior, of the classical scattering angle. We generalize our previous work by deriving, up to the fourth post-Minkowskian (4PM) level included, the explicit links between the scattering angle and the two types of potentials entering the Hamiltonian description of PM dynamics within EOB theory. We compute the scattering amplitude derived from quantizing the third post-Minkowskian (3PM) EOB radial potential (including the contributions coming from the Born iterations), and point out various subtleties in the relation between perturbative amplitudes and classical dynamics. We highlight an apparent tension between the classical 3PM dynamics derived by Bern et al. [Phys. Rev. Lett. 122, 201603 (2019)], and previous high-energy self-force results [Phys. Rev. D 86, 104041 (2012)], and propose several possible resolutions of this tension. We point out that linear-in-mass-ratio self-force…

The detection of GW170817 in gravitational waves provides unprecedented constraints on the equation of state (EOS) of the ultradense matter within the cores of neutron stars (NSs). We extend the nonparametric analysis first introduced by Landry and Essick (2019), and confirm that GW170817 favors soft EOSs. We infer macroscopic observables for a canonical $1.4\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ NS, including the tidal deformability ${\mathrm{\ensuremath{\Lambda}}}_{1.4}={211}_{\ensuremath{-}137}^{+312}$ $({491}_{\ensuremath{-}181}^{+216})$ and radius ${R}_{1.4}=10.8{6}_{\ensuremath{-}1.42}^{+2.04}$ $({12.51}_{\ensuremath{-}0.88}^{+1.00})\text{ }\mathrm{km}$, as well as the maximum mass for nonrotating NSs ${M}_{\mathrm{max}}=2.06{4}_{\ensuremath{-}0.134}^{+0.260}$ $({2.017}_{\ensuremath{-}0.087}^{+0.238})\text{ }{M}_{\ensuremath{\bigodot}}$, with nonparametric priors loosely (tightly) constrained to resemble candidate EOSs from the literature. Furthermore, we find weak evidence that GW170817 involved at least one NS based on gravitational-wave data alone…

We derive a lower bound on the merger rate of primordial black hole (PBH) binaries by estimating the maximal fraction of binaries that were perturbed between formation in the early Universe and merger, and computing a conservative merger rate of perturbed binaries. This implies robust constraints on the PBH abundance in the range $1--100{M}_{\ensuremath{\bigodot}}$. We further show that LIGO/Virgo design sensitivity has the potential to reach the PBH mass range of $1{0}^{\ensuremath{-}2}--1{0}^{3}{M}_{\ensuremath{\bigodot}}$. The constraint from the merger rate of perturbed binaries is stronger if PBHs are initially spatially clustered.

Axions are some of the best motivated particles beyond the Standard Model. We show how the attractive self-interactions of dark matter (DM) axions over a broad range of masses, from ${10}^{\ensuremath{-}22}\text{ }\text{ }\mathrm{eV}$ to ${10}^{7}\text{ }\text{ }\mathrm{GeV}$, can lead to nongravitational growth of density fluctuations and the formation of bound objects. This structure formation enhancement is driven by parametric resonance when the initial field misalignment is large, and it affects axion density perturbations on length scales of order the Hubble horizon when the axion field starts oscillating, deep inside the radiation-dominated era. This effect can turn an otherwise nearly scale-invariant spectrum of adiabatic perturbations into one that has a spike at the aforementioned scales, producing objects ranging from dense DM halos to scalar-field configurations such as solitons and oscillons. We call this class of cosmological scenarios for axion DM production ``the large-misalignment mechanism.'' We explore observational consequences of this mechanism for axions with…

We study the general infrared behavior of the power spectrum of a stochastic gravitational wave background produced by stress tensor in the form bilinear in certain dynamical degrees of freedom. We find ${\mathrm{\ensuremath{\Omega}}}_{\mathrm{GW}}\ensuremath{\propto}{k}^{3}$ for a very wide class of the sources which satisfy a set of reasonable conditions. Namely, the ${k}^{3}$ scaling is universally valid when the source term is bounded in both frequency and time, is effective in a radiation-dominated stage, and for $k$ smaller than all the physical scales associated with the source, like the peak frequency, peak width, and time duration, etc. We also discuss possible violations of these conditions and their physical implications.

The observation of binary neutron star merger GW170817, along with its optical counterpart, provided the first constraint on the Hubble constant ${H}_{0}$ using gravitational wave standard sirens. When no counterpart is identified, a galaxy catalog can be used to provide the necessary redshift information. However, the true host might not be contained in a catalog which is not complete out to the limit of gravitational-wave detectability. These electromagnetic and gravitational-wave selection effects must be accounted for. We describe and implement a method to estimate ${H}_{0}$ using both the counterpart and the galaxy catalog standard siren methods. We perform a series of mock data analyses using binary neutron star mergers to confirm our ability to recover an unbiased estimate of ${H}_{0}$. Our simulations used a simplified universe with no redshift uncertainties or galaxy clustering, but with different magnitude-limited catalogs and assumed host galaxy properties, to test our treatment of both selection effects. We explore how the incompleteness of catalogs affects the final…

We present a novel integrator based on normalizing flows which can be used to improve the unweighting efficiency of Monte Carlo event generators for collider physics simulations. In contrast to machine learning approaches based on surrogate models, our method generates the correct result even if the underlying neural networks are not optimally trained. We exemplify the new strategy using the example of Drell-Yan type processes at the LHC, both at leading and partially at next-to-leading order QCD.

The recent observation of the shadow of the supermassive black hole M87*, located at the center of the M87 galaxy, by the Event Horizon Telescope Collaboration has opened up a new window to probe the strong gravity regime. In this paper, we explicitly demonstrate the consequences of this observation on brane world black holes, characterized by existence of a negative tidal charge. Our results based on three observables associated with the shadow, namely, angular diameter, deviation from circularity, and axis ratio reveal that the existence of a negative tidal charge is more favored, possibly marking a deviation from general relativity.

The discovery of new four-dimensional black hole solutions presents a new approach to understand the Gauss-Bonnet gravity in low dimensions. In this paper, we test the Gauss-Bonnet gravity by studying the phase transition and microstructures for the four-dimensional charged anti--de Sitter black hole. In the extended phase space, where the cosmological constant and the Gauss-Bonnet coupling parameter are treated as thermodynamic variables, we find that the thermodynamic first law and the corresponding Smarr formula are satisfied. Both in the canonical ensemble and grand canonical ensemble, we observe the small-large black hole phase transition, which is similar to the case of the van der Walls fluid. This phase transition can also appear in the neutral black hole system. Furthermore, we construct the Ruppeiner geometry, and find that besides the attractive interaction, the repulsive interaction can also dominate among the microstructures for the small black hole with high temperature in a charged or neutral black hole system. This is quite different from the five-dimensional neutral…

A dark matter overdensity around a black hole may significantly alter the dynamics of the black hole's merger with another compact object. We consider here intermediate mass-ratio inspirals of stellar-mass compact objects with intermediate-mass black holes ``dressed'' with dark matter. We first demonstrate that previous estimates based on a fixed dark-matter dress are unphysical for a range of binaries and dark-matter distributions by showing that the total energy dissipated by the compact object through dynamical friction, as it inspirals through the dense dark matter environment toward the black hole, is larger than the gravitational binding energy of the dark-matter dress itself. We then introduce a new formalism that allows us to self-consistently follow the evolution of the dark-matter dress due to its gravitational interaction with the binary. We show that the dephasing of the gravitational waveform induced by dark matter is smaller than previously thought, but is still potentially detectable with the LISA space interferometer. The gravitational waves from such binaries could…

Late times dark energy transitions at redshifts $z\ensuremath{\ll}0.1$ can raise the predicted value of the Hubble constant to the SH0ES value, $74.03\ifmmode\pm\else\textpm\fi{}1.42\text{ }(\mathrm{km}\text{ }{\mathrm{s}}^{\ensuremath{-}1}\text{ }{\mathrm{Mpc}}^{\ensuremath{-}1})$ or more, while providing an equally good fit as $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ at $67.73\ifmmode\pm\else\textpm\fi{}0.41$ to higher redshift data, in particular from the cosmic microwave background and baryon acoustic oscillations. These models however do not fully resolve the true source of tension between the distance ladder and high redshift observations: the local calibration of supernovae luminosities well out into the Hubble flow. When tested in this manner by transferring the SH0ES calibration to the Pantheon supernovae dataset, the ability of such transitions to raise the Hubble constant is reduced to $69.17\ifmmode\pm\else\textpm\fi{}1.09$. Such an analysis should also be used when testing any dynamical dark energy model which can produce similarly fine features in redshift or local…

The brightness of the tip of the red-giant branch (TRGB) allows one to constrain novel energy losses that would lead to a larger core mass at helium ignition and, thus, to a brighter TRGB than expected by standard stellar models. The required absolute TRGB calibrations strongly improve with reliable geometric distances that have become available for the galaxy NGC 4258 that hosts a water megamaser and to the Large Magellanic Cloud based on 20 detached eclipsing binaries. Moreover, we revise a previous TRGB calibration in the globular cluster $\ensuremath{\omega}$ Centauri with a recent kinematical distance determination based on Gaia data release 2. All of these calibrations have similar uncertainties, and they agree with each other and with recent dedicated stellar models. Using NGC 4258 as the cleanest extragalactic case, we thus find an updated constraint on the axion-electron coupling of ${g}_{ae}<1.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}$ and…

In this paper, we construct an effective rotating loop quantum black hole (LQBH) solution, starting from the spherical symmetric LQBH by applying the Newman-Janis algorithm modified by Azreg-A\"{\i}nou's noncomplexification procedure, and study the effects of loop quantum gravity (LQG) on its shadow. Given the rotating LQBH, we discuss its horizon, ergosurface, and regularity as $r\ensuremath{\rightarrow}0$. Depending on the values of the specific angular momentum $a$ and the polymeric function $P$ arising from LQG, we find that the rotating solution we obtained can represent a regular black hole, a regular extreme black hole, or a regular spacetime without horizon (a non-black-hole solution). We also study the effects of LQG and rotation, and show that, in addition to the specific angular momentum, the polymeric function also causes deformations in the size and shape of the black hole shadow. Interestingly, for a given value of $a$ and inclination angle ${\ensuremath{\theta}}_{0}$, the apparent size of the shadow monotonically decreases, and the shadow gets more distorted with…

Estimates of the source parameters of gravitational-wave (GW) events produced by compact binary mergers rely on theoretical models for the GW signal. We present the first frequency-domain model for the inspiral, merger, and ringdown of the GW signal from precessing binary black hole systems that also includes multipoles beyond the leading-order quadrupole. Our model, PhenomPv3HM, is a combination of the higher-multipole nonprecessing model PhenomHM and the spin-precessing model PhenomPv3 that includes two-spin precession via a dynamical rotation of the GW multipoles. We validate the new model by comparing to a large set of precessing numerical-relativity simulations and find excellent agreement across the majority of the parameter space they cover. For mass ratios $<5$ the mismatch improves, on average, from $\ensuremath{\sim}6%$ to $\ensuremath{\sim}2%$ compared to PhenomPv3 when we include higher multipoles in the model. However, we find mismatches $\ensuremath{\sim}8%$ for a mass-ratio-6 and highly spinning simulation. We quantify the statistical uncertainty in the recovery of…

Working within the post-Minkowskian approach to general relativity, we prove that the radiation-reaction to the emission of gravitational waves during the large-impact-parameter scattering of two (classical) point masses modifies the conservative scattering angle by an additional contribution of order ${G}^{3}$ which involves a high-energy (or massless) logarithmic divergence of opposite sign to the one contained in the third-post-Minkowskian result of Bern et al. [Phys. Rev. Lett. 122, 201603 (2019)]. The high-energy limit of the resulting radiation-reaction-corrected (classical) scattering angle is finite, and is found to agree with the one following from the (quantum) eikonal-phase result of Amati et al. [Nucl. Phys. B347, 550 (1990)].

Phantom dark energy ($w<\ensuremath{-}1$) can produce amplified cosmic acceleration at late times, thus increasing the value of ${H}_{0}$ favored by CMB data and releasing the tension with local measurements of ${H}_{0}$. We show that the best fit value of ${H}_{0}$ in the context of the CMB power spectrum is degenerate with a constant equation-of-state parameter $w$, in accordance with the approximate effective linear equation ${H}_{0}+30.93w\ensuremath{-}36.47=0$ (${H}_{0}$ in $\mathrm{km}\text{ }{\mathrm{sec}}^{\ensuremath{-}1}\text{ }{\mathrm{Mpc}}^{\ensuremath{-}1}$). This equation is derived by assuming that both ${\mathrm{\ensuremath{\Omega}}}_{0m}{h}^{2}$ and ${d}_{A}={\ensuremath{\int}}_{0}^{{z}_{\mathrm{rec}}}\frac{dz}{H(z)}$ remain constant (for an invariant CMB spectrum) and equal to their best fit Planck/$\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ values as ${H}_{0}$, ${\mathrm{\ensuremath{\Omega}}}_{0m}$, and $w$ vary. For $w=\ensuremath{-}1$, this linear degeneracy equation leads to the best fit ${H}_{0}=67.4\text{ }\text{ }\mathrm{km}\text{…

Axion models with generation-dependent Peccei-Quinn charges can lead to flavor-changing neutral currents, thus motivating QCD axion searches at precision flavor experiments. We rigorously derive limits on the most general effective flavor-violating couplings from current measurements and assess their discovery potential. For two-body decays, we use available experimental data to derive limits on $q\ensuremath{\rightarrow}{q}^{\ensuremath{'}}a$ decay rates for all flavor transitions. Axion contributions to neutral-meson mixing are calculated in a systematic way using chiral perturbation theory and operator product expansion. We also discuss in detail baryonic decays and three-body meson decays, which can lead to the best search strategies for some of the couplings. For instance, a strong limit on the $\mathrm{\ensuremath{\Lambda}}\ensuremath{\rightarrow}na$ transition can be derived from the supernova SN 1987A. In the near future, dedicated searches for $q\ensuremath{\rightarrow}{q}^{\ensuremath{'}}a$ decays at ongoing experiments could potentially test Peccei-Quinn breaking scales…

Microlensing of stars places significant constraints on subplanetary-mass compact objects, including primordial black holes, as dark matter candidates. As the lens' Einstein radius in the source plane becomes comparable to the size of the light source, however, source amplification is strongly suppressed, making it challenging to constrain lenses with a mass at or below ${10}^{\ensuremath{-}10}$ solar masses, i.e., asteroid-mass objects. Current constraints, using Subaru Hyper Suprime Cam (HSC) observations of M31, assume a fixed source size of one solar radius. However, the actual stars in M31 bright enough to be used for microlensing are typically much larger. We correct the HSC constraints by constructing a source size distribution based on the M31 PHAT survey and on a synthetic stellar catalog and by correspondingly weighting the finite-size source effects. We find that the actual HSC constraints are weaker by up to almost 3 orders of magnitude in some cases, broadening the range of masses for which primordial black holes can be the totality of the cosmological dark matter by…

We present new results on up to sixth-order cumulants of net baryon-number fluctuations at small values of the baryon chemical potential, ${\ensuremath{\mu}}_{B}$, obtained in lattice QCD calculations with physical values of light and strange quark masses. Representing the Taylor expansions of higher-order cumulants in terms of the ratio of the two lowest-order cumulants, ${M}_{B}/{\ensuremath{\sigma}}_{B}^{2}={\ensuremath{\chi}}_{1}^{B}(T,{\ensuremath{\mu}}_{B})/{\ensuremath{\chi}}_{2}^{B}(T,{\ensuremath{\mu}}_{B})$, allows for a parameter-free comparison with data on net proton-number cumulants obtained by the STAR Collaboration in the Beam Energy Scan at RHIC. We show that recent high-statistics data on skewness and kurtosis ratios of net proton-number distributions, obtained at a beam energy $\sqrt{{s}_{NN}}=54.4\text{ }\text{ }\mathrm{GeV}$, agree well with lattice QCD results on cumulants of net baryon-number fluctuations close to the pseudocritical temperature, ${T}_{pc}({\ensuremath{\mu}}_{B})$, for the chiral transition in QCD. We also present first results from a…

This article presents an analysis and the resulting limits on light dark matter inelastically scattering off of electrons, and on dark photon and axionlike particle absorption, using a second-generation SuperCDMS high-voltage eV-resolution detector. The 0.93 g Si detector achieved a 3 eV phonon energy resolution; for a detector bias of 100 V, this corresponds to a charge resolution of 3% of a single electron-hole pair. The energy spectrum is reported from a blind analysis with 1.2 g-days of exposure acquired in an above-ground laboratory. With charge carrier trapping and impact ionization effects incorporated into the dark matter signal models, the dark matter-electron cross section ${\overline{\ensuremath{\sigma}}}_{e}$ is constrained for dark matter masses from 0.5 to ${10}^{4}\text{ }\text{ }\mathrm{MeV}/{c}^{2}$; in the mass range from 1.2 to $50\text{ }\text{ }\mathrm{eV}/{c}^{2}$ the dark photon kinetic mixing parameter $ϵ$ and the axioelectric coupling constant ${g}_{ae}$ are constrained. The minimum 90% confidence-level upper limits within the above-mentioned mass ranges are…

We present a new effective-one-body (EOB) model for eccentric binary coalescences. The model stems from the state-of-the-art model TEOBiResumS_SM for circularized coalescing black-hole binaries, that is modified to explicitly incorporate eccentricity effects both in the radiation reaction and in the waveform. Using Regge-Wheeler-Zerilli-type calculations of the gravitational wave losses as benchmarks, we find that a rather accurate ($\ensuremath{\sim}1%$) expression for the radiation reaction along mildly eccentric orbits ($e\ensuremath{\sim}0.3$) is given by dressing the current, EOB-resummed, circularized angular momentum flux, with a leading-order (Newtonian-like) prefactor valid along general orbits. An analogous approach is implemented for the waveform multipoles. The model is then completed by the usual merger-ringdown part informed by circularized numerical relativity (NR) simulations. The model is validated against the 22, publicly available, NR simulations calculated by the Simulating eXtreme Spacetime (SXS) Collaboration, with mild eccentricities, mass ratios between 1 and…

The 1965 Penrose singularity theorem demonstrates the utterly inevitable and unavoidable formation of spacetime singularities under physically reasonable assumptions, and it remains one of the main results in our understanding of black holes. It is standard lore that quantum gravitational effects will always tame these singularities in black hole interiors. However, the Penrose's theorem provides no clue as to the possible (nonsingular) geometries that may be realized in theories beyond general relativity as the result of singularity regularization. In this paper, we analyze this problem in spherically symmetric situations, being completely general otherwise, in particular regarding the dynamics of the gravitational and matter fields. Our main result is that, contrary to what one might expect, the set of regular geometries that arises is remarkably limited. We rederive geometries that have been analyzed before, but also uncover some new possibilities. Moreover, the complete catalog of possibilities that we obtain allows us to draw the novel conclusion that there is a clear tradeoff…

We study the cosmological constant ($\mathrm{\ensuremath{\Lambda}}$) in the standard $\mathrm{\ensuremath{\Lambda}}$ cold dark matter model by introducing the graduated dark energy (gDE) characterized by a minimal dynamical deviation from the null inertial mass density of the $\mathrm{\ensuremath{\Lambda}}$ in the form ${\ensuremath{\rho}}_{\text{inert}}\ensuremath{\propto}{\ensuremath{\rho}}^{\ensuremath{\lambda}}<0$ with $\ensuremath{\lambda}<1$ being a ratio of two odd integers, for which its energy density $\ensuremath{\rho}$ dynamically takes negative values in the finite past. For large negative values of $\ensuremath{\lambda}$, it creates a phenomenological model described by a smooth function that approximately describes the $\mathrm{\ensuremath{\Lambda}}$ spontaneously switching sign in the late Universe to become positive today. We confront the model with the latest combined observational datasets of $\mathrm{Planck}+\mathrm{baryon}\text{ }\mathrm{acoustic}\text{ }\mathrm{oscillations}+\mathrm{supernova}+H$. It is striking that the data predict bimodal posterior…

We discuss the footprint of evaporation of primordial black holes (PBHs) on stochastic gravitational waves (GWs) induced by scalar perturbations. We consider the case where PBHs once dominated the Universe but eventually evaporated before the big bang nucleosynthesis. The reheating through the PBH evaporation could end with a sudden change in the equation of state of the Universe compared to the conventional reheating caused by particle decay. We show that this ``sudden reheating'' by the PBH evaporation enhances the induced GWs, whose amount depends on the length of the PBH-dominated era and the width of the PBH mass function. We explore the possibility to constrain the primordial abundance of the evaporating PBHs by observing the induced GWs. We find that the abundance parameter $\ensuremath{\beta}\ensuremath{\gtrsim}{10}^{\ensuremath{-}5}\ensuremath{-}{10}^{\ensuremath{-}8}$ for $\ensuremath{\mathcal{O}}({10}^{3}\ensuremath{-}1{0}^{5})\text{ }\text{ }\mathrm{g}$ PBHs can be constrained by future GW observations if the width of the mass function is smaller than about a hundredth…

We present a critical assessment of the SN1987A supernova cooling bound on axions and other light particles. Core collapse simulations used in the literature to substantiate the bound omitted from the calculation the envelope exterior to the proto-neutron star (PNS). As a result, the only source of neutrinos in these simulations was, by construction, a cooling PNS. We show that if the canonical delayed neutrino mechanism failed to explode SN1987A, and if the precollapse star was rotating, then an accretion disk would form that could explain the late-time ($t\ensuremath{\gtrsim}5\text{ }\text{ }\mathrm{sec}$) neutrino events. Such accretion disk would be a natural feature if SN1987A was a collapse-induced thermonuclear explosion. Axions do not cool the disk and do not affect its neutrino output, provided the disk is optically thin to neutrinos, as it naturally is. These considerations cast doubt on the supernova cooling bound.

An accurate theoretical template for the galaxy power spectrum is key for the success of ongoing and future spectroscopic surveys. We examine to what extent the effective field theory (EFT) of large-scale structure is able to provide such a template and correctly estimate cosmological parameters. To that end, we initiate a blinded challenge to infer cosmological parameters from the redshift-space power spectrum of high-resolution mock catalogs mimicking the BOSS galaxy sample but covering a 100 times larger cumulative volume. This gigantic simulation volume allows us to separate systematic bias due to theoretical modeling from the statistical error due to sample variance. The challenge is to measure three unknown input parameters used in the simulation: the Hubble constant, the matter density fraction, and the clustering amplitude. We present analyses done by two independent teams, who have fitted the mock simulation data generated by yet another independent group. This allows us to avoid any confirmation bias by analyzers and to pin down possible tuning of the specific EFT…

In this work, we provide updated constraints on coupled dark energy (CDE) cosmology with Peebles-Ratra (PR) potential and constant coupling strength $\ensuremath{\beta}$. This modified gravity scenario introduces a fifth force between dark matter particles, mediated by a scalar field that plays the role of dark energy. The mass of the dark matter particles does not remain constant, but changes with time as a function of the scalar field. Here we focus on the phenomenological behavior of the model, and assess its ability to describe updated cosmological datasets that include the Planck 2018 cosmic microwave background (CMB) temperature, polarization and lensing, baryon acoustic oscillations, the Pantheon compilation of supernovae of Type Ia, data on $H(z)$ from cosmic chronometers, and redshift-space distortions. We also study the impact of the local measurement of ${H}_{0}$ from SH0ES and the strong-lensing time delay data from the H0LICOW Collaboration on the parameter that controls the strength of the interaction in the dark sector. We find a peak corresponding to a coupling…

We perform a systematic analysis of dark matter production during postinflationary reheating. Following the period of exponential expansion, the inflaton begins a period of damped oscillations as it decays. These oscillations and the evolution of temperature of the thermalized decay products depend on the shape of the inflaton potential $V(\mathrm{\ensuremath{\Phi}})$. We consider potentials of the form, ${\mathrm{\ensuremath{\Phi}}}^{k}$. Standard matter-dominated oscillations occur for $k=2$. In general, the production of dark matter may depend on either (or both) the maximum temperature after inflation, or the reheating temperature, where the latter is defined when the Universe becomes radiation dominated. We show that dark matter production is sensitive to the inflaton potential and depends heavily on the maximum temperature when $k>2$. We also consider the production of dark matter with masses larger than the reheating temperature.

We consider a low redshift ($z<0.7$) cosmological data set comprising megamasers, cosmic chronometers, type Ia supernovae and baryon acoustic oscillations, which we bin according to their redshift. For each bin, we read the value of ${H}_{0}$ by fitting directly to the flat $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model. Doing so, we find that ${H}_{0}$ descends with redshift, allowing one to fit a line with a nonzero slope of statistical significance $2.1\ensuremath{\sigma}$. Our analysis rests on the use of cosmic chronometers to break a degeneracy in baryon acoustic oscillations data and it will be imperative to revisit this feature as data improves. Nevertheless, our results provide the first independent indication of the descending trend reported by the H0LiCOW Collaboration. If substantiated going forward, early Universe solutions to the Hubble tension will struggle explaining this trend.

We study the influence of the cosmic expansion on the size of the shadow of a spinning black hole observed by a comoving observer. We first consider that the expansion is driven by a cosmological constant only and build the connection between the Kerr-de Sitter metric and the Friedmann–-Lema\^{\i}tre–-Robertson–-Walker metric. We clarify that the notion of a comoving observer is well defined in the spacetime of a spinning black hole only in the sense of being asymptotic. The angular size of the shadow for a comoving observer is calculated. Significantly we find that the angular size approaches a nonzero finite value for a distant comoving observer, while it vanishes for a distant static observer. Furthermore, by adopting the approximate method proposed in [G. S. Bisnovatyi-Kogan and O. Y. Tsupko, Phys. Rev. D 98, 084020 (2018).] we extend the study to the general multicomponent universe case. The results show that the difference between the horizontal and vertical angular size changes a lot, while their ratio, i.e., the oblateness, keeps unchanged when the supermassive spinning…

We present a joint analysis of the Planck cosmic microwave background (CMB) and Baryon Oscillation Spectroscopic Survey (BOSS) final data releases. A key novelty of our study is the use of a new full-shape (FS) likelihood for the redshift-space galaxy power spectrum of the BOSS data, based on an improved perturbation theory template. We show that the addition of the redshift-space galaxy clustering measurements breaks degeneracies present in the CMB data alone and tightens constraints on cosmological parameters. Assuming the minimal $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ cosmology with massive neutrinos, we find the following late-Universe parameters: the Hubble constant ${H}_{0}=67.9{5}_{\ensuremath{-}0.52}^{+0.66}\text{ }\text{ }\mathrm{km}\text{ }{\mathrm{s}}^{\ensuremath{-}1}\text{ }{\mathrm{Mpc}}^{\ensuremath{-}1}$, the matter density fraction ${\mathrm{\ensuremath{\Omega}}}_{m}=0.307{9}_{\ensuremath{-}0.0085}^{+0.0065}$, the mass fluctuation amplitude ${\ensuremath{\sigma}}_{8}=0.808{7}_{\ensuremath{-}0.0072}^{+0.012}$, and an upper limit on the sum of neutrino masses…

We introduce the use of autoregressive normalizing flows for rapid likelihood-free inference of binary black hole system parameters from gravitational-wave data with deep neural networks. A normalizing flow is an invertible mapping on a sample space that can be used to induce a transformation from a simple probability distribution to a more complex one: if the simple distribution can be rapidly sampled and its density evaluated, then so can the complex distribution. Our first application to gravitational waves uses an autoregressive flow, conditioned on detector strain data, to map a multivariate standard normal distribution into the posterior distribution over system parameters. We train the model on artificial strain data using a model for the gravitational-wave signal that includes inspiral, merger and ringdown and draw waveforms from a five-parameter $({m}_{1},{m}_{2},{\ensuremath{\phi}}_{0},{t}_{c},{d}_{L})$ prior and stationary Gaussian noise realizations with a fixed power spectral density. This gives performance comparable to current best deep-learning approaches to…

We explore the prospects of detecting Galactic double white dwarf (DWD) binaries with the space-based gravitational wave (GW) observatory TianQin. In this work, we analyze both a sample of currently known DWDs and a realistic synthetic population of DWDs to assess the number of guaranteed detections and the full capacity of the mission. We find that TianQin can detect 12 out of $\ensuremath{\sim}100$ known DWDs; GW signals of these binaries can be modeled in detail ahead of the mission launch, and therefore they can be used as verification sources. Besides, we estimate that TianQin has a potential to detect as many as ${10}^{4}$ DWDs in the Milky Way. TianQin is expected to measure their orbital periods and amplitudes with accuracies of $\ensuremath{\sim}{10}^{\ensuremath{-}7}$ and $\ensuremath{\sim}0.2$, respectively, and to localize on the sky a large fraction (39%) of the detected population to better than $1\text{ }\text{ }{\mathrm{deg}}^{2}$. We conclude that TianQin has the potential to significantly advance our knowledge on Galactic DWDs by increasing the sample up to 2…

The cross section for coherent elastic neutrino-nucleus scattering ($\mathrm{CE}\ensuremath{\nu}\mathrm{NS}$) depends on the response of the target nucleus to the external current, in the Standard Model (SM) mediated by the exchange of a $Z$ boson. This is typically subsumed into an object called the weak form factor of the nucleus. Here, we provide results for this form factor calculated using the large-scale nuclear shell model for a wide range of nuclei of relevance for current $\mathrm{CE}\ensuremath{\nu}\mathrm{NS}$ experiments, including cesium, iodine, argon, fluorine, sodium, germanium, and xenon. In addition, we provide the responses needed to capture the axial-vector part of the cross section, which does not scale coherently with the number of neutrons, but may become relevant for the SM prediction of $\mathrm{CE}\ensuremath{\nu}\mathrm{NS}$ on target nuclei with nonzero spin. We then generalize the formalism allowing for contributions beyond the SM. In particular, we stress that in this case, even for vector and axial-vector operators, the standard weak form factor does…

We discuss the QCD phase structure at finite temperature and chemical potential for 2-flavor and $2+1$-flavor QCD. The results are achieved by computing QCD correlation functions within a generalized functional approach that combines Dyson-Schwinger equations (DSE) and the functional renormalization group (fRG). In this setup fRG precision data from [A. K. Cyrol, M. Mitter, J. M. Pawlowski, and N. Strodthoff, Phys. Rev. D 97, 054006 (2018).] for the vacuum quark-gluon vertex and gluon propagator of 2-flavor QCD used as input, and the respective DSEs are expanded about this input. While the vacuum results for other correlation functions serve as a self-consistency check for functional approaches, the results at finite temperature and density are computed, for the first time, without the need of phenomenological infrared parameters.

In the present paper, we use the holographic approach to describe the early-time acceleration and the late-time acceleration eras of our Universe in a unified manner. Such ``holographic unification'' is found to have a correspondence with various higher curvature cosmological models with or without matter fields. The corresponding holographic cutoffs are determined in terms of the particle horizon and its derivatives, or the future horizon and its derivatives. As a result, the holographic energy density we propose is able to merge various cosmological epochs of the Universe from a holographic point of view. We find the holographic correspondence of several $F(R)$ gravity models, including axion-$F(R)$ gravity models, of several Gauss-Bonnet $F(G)$ models and finally of $F(T)$ models, and in each case we demonstrate that it is possible to describe in a unified way inflation and late-time acceleration in the context of the same holographic model.

We introduce an infinite set of jet substructure observables, derived as projections of $N$-point energy correlators, that both are convenient for experimental studies and maintain remarkable analytic properties derived from their representations in terms of a finite number of light ray operators. We show that these observables can be computed using tracking or charge information with a simple reweighting by integer moments of nonperturbative track or fragmentation functions. Our results for the projected $N$-point correlators are analytic functions of $N$, allowing us to derive resummed results to next-to-leading logarithmic accuracy for all $N$. We analytically continue our results to noninteger values of $N$ and define a corresponding analytic continuation of the observable, which we term a $\ensuremath{\nu}$ correlator, that can be measured on jets of hadrons at the LHC. This enables observables that probe the leading twist collinear dynamics of jets to be placed into a single analytic family, which we hope will lead to new insights into jet substructure.

There is irresistible observational evidence that binary systems of compact objects with at least one neutron star are progenitors of short gamma-ray bursts, as well as a production site for $r$-process elements, at least when some matter is ejected by the merger and an accretion disk is formed. The recent observations of gravitational waves in conjunction with electromagnetic counterparts fuel the need for models predicting the outcome of a given merger and the properties of the associated matter outflows as a function of the initial parameters of the binary. In this manuscript, we provide updated fitting formulas that estimate the disk mass for double neutron star binaries and ejecta masses for black hole--neutron star and double neutron star binaries, fitted to the results of numerical simulations. Our proposed fitting formulas improve on existing models by aiming for analytical simplicity, by covering a larger region of parameter space, and by accounting for regions of parameter space not covered by numerical simulations but with physically manifest merger outcomes.

We perform direct numerical simulations of magnetohydrodynamic turbulence in the early universe and numerically compute the resulting stochastic background of gravitational waves and relic magnetic fields. These simulations do not make the simplifying assumptions of earlier analytic work. If the turbulence is assumed to have an energy-carrying scale that is about a hundredth of the Hubble radius at the time of generation, as expected in a first-order phase transition, the peak of gravitational wave power will be in the mHz frequency range for a signal produced at the electroweak scale. The efficiency of gravitational wave (GW) production varies significantly with how the turbulence is driven. Detectability of turbulence at the electroweak scale by the planned Laser Interferometer Space Antenna (LISA) requires anywhere from 0.1% to 10% of the thermal plasma energy density to be in plasma motions or magnetic fields, depending on the model of the driving process. Our results predict a new universal form below the spectral peak frequency that is shallower than previously thought. This…

Novelty detection is the machine learning task to recognize data, which belong to an unknown pattern. Complementary to supervised learning, it allows us to analyze data model-independently. We demonstrate the potential role of novelty detection in collider physics, using autoencoder-based deep neural network. Explicitly, we develop a set of density-based novelty evaluators, which are sensitive to the clustering of unknown-pattern testing data or new-physics signal events, for the design of detection algorithms. We also explore the influence of the known-pattern data fluctuations, arising from nonsignal regions, on detection sensitivity. Strategies to address it are proposed. The algorithms are applied to detecting fermionic ditop partner and resonant ditop productions at LHC, and exotic Higgs decays of two specific modes at a future ${e}^{+}{e}^{\ensuremath{-}}$ collider. With parton-level analysis, we conclude that potentially the new-physics benchmarks can be recognized with high efficiency.

Given the lack of evidence for new particle discoveries at the Large Hadron Collider (LHC), it is critical to broaden the search program. A variety of model-independent searches have been proposed, adding sensitivity to unexpected signals. There are generally two types of such searches: those that rely heavily on simulations and those that are entirely based on (unlabeled) data. This paper introduces a hybrid method that makes the best of both approaches. For potential signals that are resonant in one known feature, this new method first learns a parametrized reweighting function to morph a given simulation to match the data in sidebands. This function is then interpolated into the signal region, and then the reweighted background-only simulation can be used for supervised learning as well as for background estimation. The background estimation from the reweighted simulation allows for nontrivial correlations between features used for classification and the resonant feature. A dijet search with jet substructure is used to illustrate the new method. Future applications of Simulation…

We introduce TEOBiResumS_SM, an improved version of the effective-one-body (EOB) waveform model TEOBResumS for spin-aligned, coalescing black hole binaries, that includes subdominant gravitational waveform modes completed through merger and ringdown. Beyond the dominant $(\ensuremath{\ell},|m|)=(2,2)$ one, the more robust multipoles all over the parameter space are: (2, 1), (3, 3), (3, 2), (4, 4), and (5, 5). Modes as (3, 1), (4, 3), and (4, 2) can also be generated, but are less robust. The multipolar ringdown EOB waveform stems from suitably fitting many numerical relativity (NR) waveform data from the Simulating eXtreme Spacetimes (SXS) collaboration together with test-mass waveform data. Mode-mixing effects are not incorporated. The orbital (nonspinning) part of the multipolar waveform amplitudes includes test-mass results up to (relative) 6PN order and, for most modes, is Pad\'e resummed. The $m=\mathrm{odd}$ waveform multipoles (up to $\ensuremath{\ell}=5$) incorporate most of the currently available spin-dependent analytical information. Each multipolar amplitude is…

We conduct a thorough Bayesian analysis of the possibility that the black hole merger events seen in gravitational waves are primordial black hole (PBH) mergers. Using the latest merger rate models for PBH binaries drawn from a log-normal mass function, we compute posterior parameter constraints and Bayesian evidences using data from the first two observing runs of LIGO-Virgo. We account for theoretical uncertainty due to possible disruption of the binary by surrounding PBHs, which can suppress the merger rate significantly. We also consider simple astrophysically motivated models and find that these are favored decisively over the PBH scenario, quantified by the Bayesian evidence ratio. Paying careful attention to the influence of the parameter priors and the quality of the model fits, we show that the evidence ratios can be understood by comparing the predicted chirp mass distribution to that of the data. We identify the posterior predictive distribution of chirp mass as a vital tool for discriminating between models. A model in which all mergers are PBH binaries is strongly…

The authors propose a holographic duality between a gravitational theory on a $d+1$ dimensional wedge spacetime and a $d\ensuremath{-}1$ dimensional conformal field theory (CFT), which lives on the corner of the wedge. This is a generalization of the usual AdS/CFT duality. For certain particular cases, the authors check the duality by computing the free energy, entanglement entropy and correlation functions of the dual CFTs from gravity.

Using a recently introduced method [Phys.\ Rev.\ Lett.\ {\bf 123}, 231104 (2019)], which splits the conservative dynamics of gravitationally interacting binary systems into a non-local-in-time part and a local-in-time one, we compute the local part of the dynamics at the sixth post-Newtonian (6PN) accuracy. Our strategy combines several theoretical formalisms: post-Newtonian, post-Minkowskian, multipolar-post-Minkowskian, effective-field-theory, gravitational self-force, effective one-body, and Delaunay averaging. The full functional structure of the local 6PN Hamiltonian (which involves 151 numerical coefficients) is derived, but contains four undetermined numerical coefficients. Our 6PN-accurate results are complete at orders $G^3$ and $G^4$, and the derived $O(G^3)$ scattering angle agrees, within our 6PN accuracy, with the computation of [Phys.\ Rev.\ Lett.\ {\bf 122}, no. 20, 201603 (2019)]. All our results are expressed in several different gauge-invariant ways. We highlight, and make a crucial use of, several aspects of the hidden simplicity of the mass-ratio dependence of…

The purpose of this article is twofold. First, we highlight a simple connection between the real part of quasinormal modes (QNMs) in the eikonal limit and the shadow radius of black holes (BHs) and then explore the effect of dark matter on the QNMs of massless scalar field and electromagnetic field perturbations in a BH spacetime surrounded by perfect fluid dark matter (BHPFDM). Using the Wentzel--Kramers--Brillouin (WKB) approximation, we show that the quasinormal mode spectra of BHPFDM deviate from those of Schwarzschild black hole due to the presence of the perfect fluid dark matter (PFDM) encoded by the parameter $k$. Moreover, it is shown that for any $k>0$ the real part and the absolute value of the imaginary part of QNM frequencies increases, and this means that the field perturbations in the presence of PFDM decay more rapidly compared to the Schwarzschild vacuum BH. We point out that there exists a reflecting point ${k}_{0}$ corresponding to maximal values for the real part of QNM frequencies. Namely, as the PFDM parameter $k$ increases in the interval $k<{k}_{0}$, the QNM…

There are emerging tensions for theory results of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment both within recent lattice QCD calculations and between some lattice QCD calculations and R-ratio results. In this paper, we work toward scrutinizing critical aspects of these calculations. We focus in particular on a precise calculation of Euclidean position-space windows defined by RBC/UKQCD that are ideal quantities for cross-checks within the lattice community and with R-ratio results. We perform a lattice QCD calculation using physical up, down, strange, and charm sea quark gauge ensembles generated in the staggered formalism by the MILC Collaboration. We study the continuum limit using inverse lattice spacings from ${a}^{\ensuremath{-}1}\ensuremath{\approx}1.6\text{ }\text{ }\mathrm{GeV}$ to 3.5 GeV, identical to recent studies by FNAL/HPQCD/MILC and Aubin et al. and similar to the recent study of BMW. Our calculation exhibits a tension for the particularly interesting window result of…

We evaluate the gluon and quark contributions to the spin of the proton using an ensemble of gauge configurations generated at physical pion mass. We compute all valence and sea quark contributions to high accuracy. We perform a nonperturbative renormalization for both quark and gluon matrix elements. We find that the contribution of the up, down, strange, and charm quarks to the proton intrinsic spin is $\frac{1}{2}{\ensuremath{\sum}}_{q=u,d,s,c}\mathrm{\ensuremath{\Delta}}{\mathrm{\ensuremath{\Sigma}}}^{{q}^{+}}=0.191(15)$ and to the total spin ${\ensuremath{\sum}}_{q=u,d,s,c}{J}^{{q}^{+}}=0.285(45)(10)$. The gluon contribution to the spin is ${J}^{g}=0.187(46)(10)$ yielding $J={J}^{q}+{J}^{g}=0.473(71)(14)$ confirming the spin sum. The momentum fraction carried by quarks in the proton is found to be 0.618(60) and by gluons 0.427(92), the sum of which gives 1.045(118) confirming the momentum sum rule. All scale and scheme dependent quantities are given in the $\overline{\mathrm{MS}}$ scheme at 2 GeV.

This paper is devoted to discussing compact stars in $f(\mathcal{R},\mathcal{G})$ gravity, where $\mathcal{R}$ and $\mathcal{G}$ denote the Ricci scalar and Gauss-Bonnet invariant, respectively. To meet this aim, we consider spherically symmetric space-time with an anisotropic fluid distribution. In particular, the Karmarkar condition is used to explore the compact star solutions. Furthermore, we choose two specific models of compact stars, namely LMC X-4 ($\mathrm{mass}=1.29M/{M}_{\ensuremath{\bigodot}}$ and $\mathrm{radii}=9.711\text{ }\text{ }\mathrm{km}$) and EXO 1785-248 ($\mathrm{mass}=1.30M/{M}_{\ensuremath{\bigodot}}$ and $\mathrm{radii}=8.849\text{ }\text{ }\mathrm{km}$). We develop the field equations for $f(\mathcal{R},\mathcal{G})$ gravity by employing the Karmarkar condition with a specific model already reported in literature by Lake [Phys. Rev. D 67, 104015 (2003)]. We further consider the Schwarzschild geometry for the matching conditions at the boundary. It is important to mention here that we calculate the values of all the involved parameters by imposing the…

In this work we study the axial contributions to the hadronic light-by-light piece of the muon anomalous magnetic moment. We point out some theoretical ambiguities in previous estimates, and opt to perform a new evaluation using resonace chiral theory, that is free of them. As a result, we obtain ${a}_{\ensuremath{\mu}}^{\text{HLbL};A}=\phantom{\rule{0ex}{0ex}}(0.{8}_{\ensuremath{-}0.8}^{+3.5})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$, that might suggest a smaller value than most recent calculations, underlining the relevance of the off-shell prescription and the need for future work along this direction. Further, we find that our results depend critically on the asymptotic behavior of the form factors, and as such, emphasizes the relevance of future experiments at large photon virtualities. In addition, we present general results regarding the involved axial form factors description, comprehensively examining (and relating) the current approaches, that shall be of general interest.

We calculate the contribution to the muon anomalous magnetic moment hadronic vacuum polarization from the connected diagrams of up and down quarks, omitting electromagnetism. We employ QCD gauge-field configurations with dynamical $u$, $d$, $s$, and $c$ quarks and the physical pion mass, and analyze five ensembles with lattice spacings ranging from $a\ensuremath{\approx}0.06$ to 0.15 fm. The up- and down-quark masses in our simulations have equal masses ${m}_{l}$. We obtain, in this world where all pions have the mass of the ${\ensuremath{\pi}}^{0}$, $1{0}^{10}{a}_{\ensuremath{\mu}}^{ll}(\mathrm{conn}.)=637.8(8.8)$, in agreement with independent lattice-QCD calculations. We then combine this value with published lattice-QCD results for the connected contributions from strange, charm, and bottom quarks, and an estimate of the uncertainty due to the fact that our calculation does not include strong-isospin breaking, electromagnetism, or contributions from quark-disconnected diagrams. Our final result for the total $\mathcal{O}({\ensuremath{\alpha}}^{2})$ hadronic-vacuum polarization…

Recent theoretical work indicates that the neutrino radiation in core-collapse supernovae may be susceptible to flavor instabilities that set in far behind the shock, grow extremely rapidly, and have the potential to profoundly affect supernova dynamics and composition. Here we analyze the nonlinear collective oscillations that are prefigured by these instabilities. We demonstrate that a zero crossing in ${n}_{{\ensuremath{\nu}}_{e}}\ensuremath{-}{n}_{{\overline{\ensuremath{\nu}}}_{e}}$ as a function of propagation angle is not sufficient to generate instability. Our analysis accounts for this fact and allows us to formulate complementary criteria. Using fornax simulation data, we show that fast collective oscillations qualitatively depend on how forward peaked the neutrino angular distributions are.

A study of the lineshape of the ${\ensuremath{\chi}}_{c1}(3872)$ state is made using a data sample corresponding to an integrated luminosity of $3\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected in $pp$ collisions at center-of-mass energies of 7 and 8 TeV with the LHCb detector. Candidate ${\ensuremath{\chi}}_{c1}(3872)$ and $\ensuremath{\psi}(2S)$ mesons from $b$-hadron decays are selected in the $J/\ensuremath{\psi}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting between the ${\ensuremath{\chi}}_{c1}(3872)$ and $\ensuremath{\psi}(2S)$ states, $\mathrm{\ensuremath{\Delta}}m$, and the width of the ${\ensuremath{\chi}}_{c1}(3872)$ state, ${\mathrm{\ensuremath{\Gamma}}}_{\mathrm{BW}}$, are determined to be $\genfrac{}{}{0}{}{\mathrm{\ensuremath{\Delta}}m=185.598\ifmmode\pm\else\textpm\fi{}0.067\ifmmode\pm\else\textpm\fi{}0.068\text{ }\text{ }\mathrm{MeV},}{{\mathrm{\ensuremath{\Gamma}}}_{\mathrm{BW}}=1.39\ifmmode\pm\else\textpm\fi{}0.24\ifmmode\pm\else\textpm\fi{}0.10\text{…

Signal extraction out of background noise is a common challenge in high-precision physics experiments, where the measurement output is often a continuous data stream. To improve the signal-to-noise ratio of the detection, witness sensors are often used to independently measure background noises and subtract them from the main signal. If the noise coupling is linear and stationary, optimal techniques already exist and are routinely implemented in many experiments. However, when the noise coupling is nonstationary, linear techniques often fail or are suboptimal. Inspired by the properties of the background noise in gravitational wave detectors, this work develops a novel algorithm to efficiently characterize and remove nonstationary noise couplings, provided there exist witnesses of the noise source and of the modulation. In this work, the algorithm is described in its most general formulation, and its efficiency is demonstrated with examples from the data of the Advanced LIGO gravitational-wave observatory, where we could obtain an improvement of the detector gravitational-wave reach…

In this paper, we study the weak gravitational deflection angle of relativistic massive particles by the Kerr-like black hole in the bumblebee gravity model. In particular, we focus on weak-field limits and calculate the deflection angle for a receiver and source at a finite distance from the lens. To this end, we use the Gauss-Bonnet theorem of a two-dimensional surface defined by a generalized Jacobi metric. The spacetime is asymptotically nonflat due to the existence of a bumblebee vector field. Thus, the deflection angle is modified and can be divided into three parts: the surface integral of the Gaussian curvature, the path integral of a geodesic curvature of the particle ray, and the change in the coordinate angle. In addition, we also obtain the same results by defining the deflection angle. The effects of the Lorentz breaking constant on the gravitational lensing are analyzed. In particular, we correct a mistake in the previous literature. Furthermore, we consider the finite-distance correction for the deflection angle of massive particles.