We study gravitational radiation produced by time-changing matter source in de Sitter spacetime. We consider a cosmological Killing horizon instead of the conformal boundary used in the radiation theory in the Minkowski spacetime. The energy of the radiation passing through the horizon is derived. Our result takes the form of a generalized quadrupole formula expressed in terms of the mass and pressure quadrupole moments and is written explicitly up to the first order in $\sqrt{\mathrm{\Lambda }}$. The zeroth-order term recovers the famous Einstein’s quadrupole formula obtained for the perturbed Minkowski spacetime, whereas the first-order term is a new correction.

We address the issue of black hole scalarization and its compatibility with cosmic inflation and big bang cosmology from an effective field theory (EFT) point of view. In practice, using a well-defined and healthy toy model which (in part) has been broadly considered in the literature, we consider how higher-order theories of gravity, up to cubic operators in Riemann curvature, fit within this context. Interestingly enough, we find that already at this minimal level, there is a nontrivial interplay between the Wilson coefficients which are otherwise completely independent, constraining the parameter space where scalarization may actually occur. Conclusively, we claim that the EFT does exhibit black hole scalarization, remaining compatible with the inflationary paradigm, and admitting general relativity as a cosmological attractor.

We generalize the symmetron screening mechanism by allowing for an explicit symmetry breaking of the symmetron ${\varphi }^4$ potential. A coupling to matter of the form $A(\varphi )=1+\frac{{\varphi }^2}{M^2}$ leads to an explicitly broken symmetry with effective potential $V_{\mathrm{eff}}(\varphi )=-{\mu }^2(1-\frac{\rho }{{\mu }^2{M}^2}){\varphi }^2+\frac{\lambda }{2}{\varphi }^4+2ϵ{\varphi }^3+\frac{\lambda }{2}{\eta }^4$ (where $\eta$ and $ϵ$ are free parameters to be fixed). Because of the explicit symmetry breaking induced by the cubic term, we call this field the “asymmetron.” For large matter density $\rho >{\rho }_{*}$, the effective potential has a single minimum at $\varphi =0$, leading to restoration of general relativity as in the usual symmetron screening mechanism. For low matter density, however, there is a false vacuum and a single true vacuum due to the explicit symmetry breaking. This is expected to lead to an unstable network of domain walls with slightly different values of the gravitational constant $G$ on each side of the wall. This network would be in constant interaction with matter overdensities and would lead to interesting observational signatures which could be detected as gravitational and expansion rate transitions in redshift space. Such a gravitational transition has been recently proposed for the resolution of the Hubble tension.

In most direct detection experiments, the free nuclear recoil description of dark matter scattering breaks down for masses $\lesssim 100\mathrm{MeV}$, or when the recoil energy is comparable to a few times the typical phonon energy For dark matter lighter than 1 MeV, scattering via excitation of a single phonon dominates and has been computed previously, but for the intermediate mass range or higher detector thresholds, multiphonon processes dominate. We perform the first calculation of the scattering rate via multiphonon production for the entire keV-GeV dark matter mass range, assuming a harmonic crystal target. We provide an analytic description that connects the single phonon, multiphonon, and the nuclear recoil regimes. Our results are implemented in the public package darkelf.

In the framework of large-momentum effective theory at one-loop matching accuracy, we perform a lattice calculation of the Collins-Soper kernel, which governs the rapidity evolution of transverse-momentum-dependent (TMD) distributions. We first obtain the quasi-TMD wave functions at three different meson momenta, on a lattice with valence clover quarks on a dynamical highly improved staggered quark sea and lattice spacing $a=0.12\mathrm{fm}$ from the MILC Collaboration, and renormalize the pertinent linear divergences using Wilson loops. Through one-loop matching to the light-cone wave functions, we determine the Collins-Soper kernel with transverse separation up to 0.6 fm. We study the systematic uncertainties from operator mixing and scale dependence, as well as the impact from higher power corrections. Our results potentially allow for a determination of the soft function and other transverse-momentum-dependent quantities at one-loop accuracy.

We present a mechanism for ${\mathrm{\Omega }}_c\to {\pi }^{+}\mathrm{\Omega }(2012)$ production through an external emission Cabibbo favored weak decay mode, where the $\mathrm{\Omega }(2012)$ is dynamically generated from the interaction of $\overline{K}{\mathrm{\Xi }}^{*}(1530)$ and $\eta \mathrm{\Omega }$, with $\overline{K}\mathrm{\Xi }$ as the main decay channel. The $\mathrm{\Omega }(2012)$ decays later to $\overline{K}\mathrm{\Xi }$ in this picture, with results compatible with Belle data. As a consequence, one can evaluate the direct decay ${\mathrm{\Omega }}_c^0\to {\pi }^{+}{K}^{-}{\mathrm{\Xi }}^0$ and the decay ${\mathrm{\Omega }}_c^0\to {\pi }^{+}\overline{K}{\mathrm{\Xi }}^{*}$, ${\pi }^{+}\eta \mathrm{\Omega }$ with direct couplings of $\overline{K}{\mathrm{\Xi }}^{*}$ and $\eta \mathrm{\Omega }$ to $K^{-}{\mathrm{\Xi }}^0$. We show that, within uncertainties and using data from a recent Belle measurement, all three channels account for about (12–20)% of the total ${\mathrm{\Omega }}_c\to {\pi }^{+}{K}^{-}{\mathrm{\Xi }}^0$ decay rate. The consistency of the molecular picture with all the data is established by showing that ${\mathrm{\Omega }}_c\to {\mathrm{\Xi }}^0{\overline{K}}^{*0}\to {\mathrm{\Xi }}^0{K}^{-}{\pi }^{+}$ and ${\mathrm{\Omega }}_c\to {\pi }^{+}{\mathrm{\Omega }}^{*}\to {\pi }^{+}{K}^{-}{\mathrm{\Xi }}^0$ account for about 85% of the total ${\mathrm{\Omega }}_c\to {\pi }^{+}{K}^{-}{\mathrm{\Xi }}^0$.

The hadronic decay ${\eta }_c(2S)\to 3({\pi }^{+}{\pi }^{-})$ is observed with a statistical significance of 9.3 standard deviations using $(448.1\pm 2.9)\times {10}^6\psi (3686)$ events collected by the BESIII detector at the BEPCII collider. The measured mass and width of ${\eta }_c(2S)$ are $(3643.4\pm 2.3(\mathrm{stat})\pm 4.4(\mathrm{syst}))\mathrm{MeV}/c^2$ and $(19.8\pm 3.9(\mathrm{stat})\pm 3.1(\mathrm{syst}))\mathrm{MeV}$, respectively, which are consistent with the world average values within two standard deviations. The product branching fraction $\mathcal{B}[\psi (3686)\to \gamma {\eta }_c(2S)]\times \mathcal{B}[{\eta }_c(2S)\to 3({\pi }^{+}{\pi }^{-})]$ is measured to be $(9.2\pm 1.0(\mathrm{stat})\pm 1.2(\mathrm{syst}))\times {10}^{-6}$. Using $\mathcal{B}[\psi (3686)\to \gamma {\eta }_c(2S)]=(7.0_{-2.5}^{+3.4})\times {10}^{-4}$, we obtain $\mathcal{B}[{\eta }_c(2S)\to 3({\pi }^{+}{\pi }^{-})]=(1.31\pm 0.15(\mathrm{stat})\pm 0.17(\mathrm{syst})(\genfrac{}{}{0ex}{}{+0.64}{-0.47})(\mathrm{extr}))\times {10}^{-2}$, where the third uncertainty is from $\mathcal{B}[\psi (3686)\to \gamma {\eta }_c(2S)]$. We also measure the ${\chi }_{cJ}\to 3({\pi }^{+}{\pi }^{-})$ ($J=0$, 1, 2) decays via ${\psi }^{\prime }\to \gamma {\chi }_{cJ}$ transitions. The branching fractions are $\mathcal{B}[{\chi }_{c0}\to 3({\pi }^{+}{\pi }^{-})]=(2.080\pm 0.006(\mathrm{stat})\pm 0.068(\mathrm{syst}))\times {10}^{-2}$, $\mathcal{B}[{\chi }_{c1}\to 3({\pi }^{+}{\pi }^{-})]=(1.092\pm 0.004(\mathrm{stat})\pm 0.035(\mathrm{syst}))\times {10}^{-2}$, and $\mathcal{B}[{\chi }_{c2}\to 3({\pi }^{+}{\pi }^{-})]=(1.565\pm 0.005(\mathrm{stat})\pm 0.048(\mathrm{syst}))\times {10}^{-2}$.

We study analytic continuations of holographic renormalization group (RG) flows beyond their infrared (IR) fixed points. Such “trans-IR” flows are a natural framework for describing physics inside of black holes. First, we construct a monotonic holographic $a$-function which counts degrees of freedom along a trans-IR flow. Using this function, we argue that the degrees of freedom “thin out” and vanish when flowing to a trans-IR endpoint, represented by a Kasner singularity. We then recast well-studied quantum information probes in the language of trans-IR flows, finding that entanglement and complexity from volume generally fail to fully probe the trans-IR while 2-point correlations and complexity from action generally do so in a complementary manner.

We study the thermalization of a scalar field $\mathrm{\Phi }$ coupled to two other scalar fields ${\chi }_{1,2}$ that constitute a bath in thermal equilibrium. For a range of masses the $\mathrm{\Phi }$ propagator features threshold and infrared divergences, a vanishing residue at the (quasi)particle pole, and vanishing on-shell decay rates thereby preventing the equilibration of $\mathrm{\Phi }$ with the bath via on-shell processes. Inspired by the theory of quantum open systems we obtain a quantum master equation for the reduced density matrix of $\mathrm{\Phi }$ that includes the time dependence of bath correlations, yielding time dependent rates in the dynamics of relaxation and allowing virtual processes with an energy $q_0$ whose difference from the on-shell energy is of $\mathcal{O}(1/t)$ at long time $t$. These off-shell processes lead to thermalization despite vanishing $S$-matrix rates. In the case of threshold divergences we find that a thermal fixed point is approached as $e^{-\sqrt{t/t^{*}}}$ with the relaxation time $t^{*}$ becoming shorter at high temperature as a consequence of stimulated emission and absorption. In the infrared case, the thermal fixed point is approached as $e^{-\gamma (t)}$, where $\gamma (t)$ features a crossover between $\ln (t)$ and $t$ behavior for $t\gg 1/T$. The vanishing of the residue and the crossover in relaxational dynamics in this case is strikingly reminiscent of the orthogonality catastrophe in heavy impurity systems. The results yield more general lessons on thermalization via virtual processes.

In this paper, we consider the tachyonic instability of Kerr-Newman (KN) black holes in the Einstein-Maxwell-scalar (EMS) theory with nonminimal negative scalar coupling to Maxwell term, and then obtain a bound $(\frac{a}{r_{+}}\ge 0.4142)$ for spin parameter $a$ of a KN black hole in the limit of coupling constant $\alpha \to -\infty$ by using analytical method. In addition, we perform a ($2+1$)-dimensional time evolution of linearized scalar field perturbation on the KN black hole background by implementing the hyperboloidal foliation method numerically in the EMS theory. It recovers the spontaneous scalarization phenomenon for KN black hole in some certain regions of the parameter spaces. We further plot corresponding threshold curves $\alpha (a)$ which describe a boundary between bald KN black holes and scalarized spinning black holes in the EMS theory.

We compute the graybody factor and evaporation rate of a rotating black hole in the presence of a hypothetical reflective surface slightly outside the outer horizon radius, assuming that it spontaneously emits thermal radiation due to quantum-gravitational effects such as firewalls or stretched horizons. As a result of a resonance caused by a cavity between the reflective surface and angular momentum barrier, the graybody factor is subject to a modulation in the frequency space. By taking into account this effect for multiangular modes of neutrinos, photons, and gravitons, we numerically compute the time development of the mass and angular momentum of the black hole, and show that the excited reflective surface shortens the lifetime of quantum black holes.

We explore the possibility of gravitationally generated particle production in the scalar-tensor representation of $f(R,T)$ gravity. Due to the explicit nonminimal curvature-matter coupling in the theory, the divergence of the matter energy-momentum tensor does not vanish. We explore the physical and cosmological implications of this property by using the formalism of irreversible thermodynamics of open systems in the presence of matter creation/annihilation. The particle creation rates, pressure, temperature evolution, and the expression of the comoving entropy are obtained in a covariant formulation and discussed in detail. Applied together with the gravitational field equations, the thermodynamics of open systems lead to a generalization of the standard $\mathrm{\Lambda }\mathrm{CDM}$ cosmological paradigm, in which the particle creation rates and pressures are effectively considered as components of the cosmological fluid energy-momentum tensor. We also consider specific models, and compare the scalar-tensor $f(R,T)$ cosmology with the $\mathrm{\Lambda }\mathrm{CDM}$ scenario and the observational data for the Hubble function. The properties of the particle creation rates, of the creation pressures, and entropy generation through gravitational matter production are further investigated in both the low and high redshift limits.

With the improvement in sensitivity of gravitational wave (GW) detectors and the increasing diversity of GW sources, there is a strong need for accurate GW waveform models for data analysis. While the current model accuracy assessments require waveforms generated by numerical relativity (NR) simulations as the “true waveforms,” in this paper we propose an assessment approach that does not require NR simulations, which enables us to assess model accuracy everywhere in the parameter space. By measuring the difference between two waveform models, we derive a necessary condition for a pair of waveform models to both be accurate, for a particular set of parameters. We then apply this method to the parameter estimation samples of the Gravitational-Wave Transient Catalogs GWTC-3 and GWTC-2.1, and find that the waveform accuracy for high signal-to-noise ratio events in some cases fails our assessment criterion. Based on analysis of real events’ posterior samples, we discuss the correlation between our quantified accuracy assessments and systematic errors in parameter estimation. We find that waveform models that perform worse in our assessment are more likely to give inconsistent estimations. We also investigate waveform accuracy in different parameter regions, and find that the accuracy degrades as the spin effects go up, the mass ratio deviates from one, or the orbital plane is nearly aligned with the line of sight. Furthermore, we make predictions of waveform accuracy requirements for future detectors and find that the accuracy of current waveform models should be improved by at least 3 orders of magnitude, which is consistent with previous works.

We demonstrate that observations of the gravitational memory from core collapse supernovae at future deci-Hz interferometers enable time-triggered searches of supernova neutrinos at Mt-scale detectors. Achieving a sensitivity to characteristic strains of at least $\sim {10}^{-25}$ at $f\simeq 0.3\mathrm{Hz}$—e.g., by improving the noise of DECIGO by one order of magnitude—will allow robust time triggers for supernovae at distances $D\sim 40–300\mathrm{Mpc}$, resulting in a nearly background-free sample of $\sim 3–70$ neutrino events per Mt per decade of operation. This sample would bridge the sensitivity gap between rare galactic supernova bursts and the cosmological diffuse supernova neutrino background, allowing detailed studies of the neutrino emission of supernovae in the local Universe.

The millisecond pulsars, old-recycled objects spinning with high frequency $\mathcal{O}$ (kHz) sustaining the deformation from their spherical shape, may emit gravitational waves (GW). These are one of the potential candidates contributing to the anisotropic stochastic gravitational-wave background (SGWB) observable in the ground-based GW detectors. Here, we present the results from a likelihood-based targeted search for the SGWB due to millisecond pulsars in the Milky Way, by analyzing the data from the first three observing runs of Advanced LIGO and Advanced Virgo detector. We assume that the shape of SGWB power spectra and the sky distribution is known a priori from the population synthesis model. The information of the ensemble source properties, i.e., the in-band number of pulsars, $N_{\mathrm{obs}}$ and the averaged ellipticity, ${\mu }_{\epsilon }$ is encoded in the maximum likelihood statistic. We do not find significant evidence for the SGWB signal from the considered source population. The best Bayesian upper limit with 95% confidence for the parameters are $N_{\mathrm{obs}}\le 8.8\times {10}^4$ and ${\mu }_{ϵ}\le 1.4\times 10^{-6}$, which is comparable to the bounds on mean ellipticity with the GW observations of the individual pulsars. Finally, we show that for the plausible case of $N_{\mathrm{obs}}=40000$, with the one year of observations, the one-sigma sensitivity on ${\mu }_{\epsilon }$ might reach $1.5\times 10^{-7}$ and $4.1\times 10^{-8}$ for the second-generation detector network having $\mathrm{A}+$ sensitivity and third-generation detector network, respectively.

We study the ${\mathrm{\Xi }}_b(6100)$ using the methods of QCD sum rules and light-cone sum rules within the framework of heavy quark effective theory. Our results suggest that the ${\mathrm{\Xi }}_b(6100)$ can be well interpreted as the $P$-wave bottom baryon of $J^P=3/2^{-}$, belonging to the $SU(3)$ flavor ${\overline{\mathbf{3}}}_F$ representation. It has a partner state of $J^P=1/2^{-}$, labeled as ${\mathrm{\Xi }}_b(1/2^{-})$, whose mass and width are predicted to be $m_{{\mathrm{\Xi }}_b(1/2^{-})}={6.08}_{-0.11}^{+0.13}\mathrm{GeV}$ and ${\mathrm{\Gamma }}_{{\mathrm{\Xi }}_b(1/2^{-})}=4_{-4}^{+29}\mathrm{MeV}$, respectively, with the mass splitting $\mathrm{\Delta }M=m_{{\mathrm{\Xi }}_b(6100)}-m_{{\mathrm{\Xi }}_b(1/2^{-})}=9\pm 3\mathrm{MeV}$. We propose to search for it in the ${\mathrm{\Xi }}_c({1/2}^{-})\to {\mathrm{\Xi }}_b^{\prime }\pi$ decay channel. Our results also suggest that the ${\mathrm{\Lambda }}_b(5912)$ and ${\mathrm{\Lambda }}_b(5920)$ are their partner states with $J^P=1/2^{-}$ and $3/2^{-}$, respectively, and, moreover, the ${\mathrm{\Lambda }}_c(2595)$, ${\mathrm{\Lambda }}_c(2625)$, ${\mathrm{\Xi }}_c(2790)$, and ${\mathrm{\Xi }}_c(2815)$ are their charmed partner states.

We introduce a freeze-out procedure to convert the critical fluctuations in a droplet of quark-gluon plasma (QGP) that has, as it expanded and cooled, passed close to a posited critical point on the phase diagram into cumulants of hadron multiplicities that can subsequently be measured. The procedure connects the out-of-equilibrium critical fluctuations described in concert with the hydrodynamic evolution of the droplet of QGP by extended hydrodynamics, known as $\text{Hydro}+$, with the subsequent kinetic description in terms of observable hadrons. We introduce a critical scalar isoscalar field sigma whose fluctuations cause correlations between observed hadrons due to the couplings of the sigma field to the hadrons via their masses. We match the QGP fluctuations obtained by solving the $\text{Hydro}+$ equations describing the evolution of critical fluctuations before freeze-out to the correlations of the sigma field. In turn, these are imprinted onto correlations and fluctuations in the multiplicity of hadrons, most importantly protons, after freeze-out via the generalization of the familiar half-century-old Cooper-Frye freeze-out prescription which we introduce. The proposed framework allows us to study the effects of critical slowing down and the consequent deviation of the observable predictions from equilibrium expectations quantitatively. We also quantify the suppression of cumulants due to conservation of baryon number. We demonstrate the procedure in practice by freezing out a $\text{Hydro}+$ simulation in an azimuthally symmetric and boost invariant background that includes radial flow discussed in Rajagopal et al. [Phys. Rev. D 102, 094025 (2020)].

We discuss the possibilities of distinguishing among different mechanisms of neutrinoless double beta decay arising in the effective field theory framework. Following the review and detailed investigation of the particular ways of discrimination, we conclude that the 32 different low-energy effective operators can be split into multiple groups that are in principle distinguishable from each other by measurements of the phase-space observables and by comparison of the decay rates obtained using different isotopes. This would require not only a substantial experimental precision but necessarily also a considerable improvement of the current theoretical knowledge of the underlying nuclear physics. Specifically, the limiting aspect in our approach turns out to be the currently unknown or uncertain values of low-energy constants. Besides the study adopting the effective field theory language we also look into several typical UV models.

A fluid-dynamic approach to the diffusion of heavy quarks in the quark-gluon plasma (QGP) is presented. Specifically, we analyze the Fokker-Planck equation for the momentum transport of heavy quarks from a fluid perspective and use a mapping to second-order fluid dynamics to determine conductivities and relaxation times governing their spatial diffusion. By investigating the relation between the two approaches, we provide new insights concerning the level of local thermalization of charm and bottom quarks inside the expanding QGP. Our results indicate that a fluid-dynamic description of diffusion is feasible for charm quarks at least for the latest stages of the fireball evolution.

In both flat and curved spacetimes, there are weak and strong versions of the anti-Unruh/anti-Hawking effects, in which the Kubo-Martin-Schwinger field temperature is anticorrelated with the response of a detector and its inferred temperature. We investigate for the first time the effects on the weak and strong anti-Hawking effects for an Unruh-DeWitt detector orbiting a Banados-Teitelboim-Zanelli black hole in the corotating frame. We find that rotation can significantly amplify the strength of the weak anti-Hawking effect, whereas it can either amplify or reduce the strength of the strong anti-Hawking effect depending on boundary conditions. For the strong anti-Hawking effect, we find a nonmonotonic relationship between the angular momentum and detector temperature for each boundary condition. In addition, we note that the weak anti-Hawking effect is independent of a changing AdS length, while a longer AdS length increases the temperature range of the strong anti-Hawking effect.