We study a possibility of constraining isotropic cosmic birefringence with help of cosmic microwave background polarization data in the presence of polarization angle miscalibration without relying on any assumptions about the Galactic foreground angular power spectra and in particular, on the correlation between their E- and B-modes. For this purpose, we propose a new analysis framework based on a generalized parametric component separation approach, which accounts simultaneously on the presence of Galactic foregrounds, relevant instrumental effects, and external priors. We find that upcoming multifrequency cosmic microwave background (CMB) data with appropriate calibration priors will allow producing an instrumental-effect-corrected and foreground-cleaned CMB map, which can be used to estimate the isotropic birefringence angle and the tensor-to-scalar ratio, accounting on statistical and systematic uncertainties incurred during the entire procedure. In particular, in the case of a Simons Observatory-like, three small aperture telescopes, we derive an uncertainty on the birefringence angle of $\sigma ({\beta }_b)=0.07°$ (0.1°), assuming the standard cosmology and calibration priors for all (one) frequency channels with the precision of $\sigma ({\alpha }_i)=0.1°$ as aimed at by the near future ground-based multifrequency experiments. This implies that these experiments could confirm or disprove the recently detected value of ${\beta }_b=0.35°$ with a significance between 3 and $5\sigma$. We furthermore explore the impact of precision of the calibration priors and of foreground complexity on our results and discuss requirements on the calibration precision. In addition, we also investigate constraints on the tensor-to-scalar ratio, $r$, which can be derived in the presence of isotropic birefringence and/or polarization angle miscalibration. We find that the proposed method allows setting constraints on $r$ in such cases, even if no prior is available, and with only a minor increase of the final uncertainty as compared to cases without these effects.

Inclusive hadronic decays of the $\tau$ lepton are very interesting from the phenomenological point of view since they give access to the Cabibbo-Kobayashi-Maskawa matrix elements $V_{ud}$ and $V_{us}$. In this paper, for the first time, by employing the method of [M. Hansen, A. Lupo, and N. Tantalo, Phys. Rev. D 99, 094508 (2019)] for hadronic smeared spectral densities, we compute on the lattice the inclusive decay rate of the processes $\tau \to X_{ud}{\nu }_{\tau }$, where $X_{ud}$ is a generic hadronic state with $\overline{u}d$ flavor quantum numbers. Our computation, which avoids any recourse to operator product expansion and/or perturbative approximations, is carried out in isospin symmetric $N_f=2+1+1$ lattice QCD at physical quark masses, using ensembles produced by the Extended Twisted Mass Collaboration at three lattice spacings and two volumes. All uncertainties, except for isospin breaking effects, are taken into account and a result with a subpercent error is obtained for $|V_{ud}|$, which is nicely consistent with the current world average. These findings validate our approach and also motivate the inclusion of isospin breaking corrections and its extension to the inclusive decay $\tau \to X_{us}{\nu }_{\tau }$, paving the way toward a high-precision first-principles determination of $|V_{us}|$ and $|V_{ud}|$ from inclusive $\tau$ decay.

We give details of our study as to whether high-energy gluon showers inside a QCD medium can be treated as a sequence of individual splitting processes $g\to gg$, or whether there is significant quantum overlap between where one splitting ends and the next begins (neglecting effects that can be absorbed into an effective value of the jet-quenching parameter $\widehat{q}$ that characterizes the medium). The study is carried out by imagining in-medium gluon-shower development in the simplest theoretical situation, which includes imagining a very large, static, homogeneous medium and taking the large $N_{\mathrm{c}}$ limit. Along the way, we also show how in-medium shower evolution can be written in terms of a “net” splitting rate $[d\mathrm{\Gamma }/dx{]}_{\mathrm{net}}$, and we provide a moderately simple analytic fit to our numerical results for the overlap effects included in that rate, which we hope may be of use to others wishing to study possible consequences of overlapping splittings.

In holographic duality an eternal Anti-de Sitter black hole is described by two copies of the boundary Conformal Field Theory in the thermal field double state. In this paper we provide explicit constructions in the boundary theory of infalling time evolutions which can take bulk observers behind the horizon. The constructions also help to illuminate the boundary emergence of the black hole horizons, the interiors, and the associated causal structure. A key element is the emergence, in the large $N$ limit of the boundary theory, of a type ${\mathrm{III}}_1$ von Neumann algebraic structure from the type I boundary operator algebra and the half-sided modular translation structure associated with it.

In holographic duality an eternal anti–de Sitter black hole is described by two copies of the boundary conformal field theory in the thermal field double state. This identification has many puzzles, including the boundary descriptions of the event horizons, the interiors of the black hole, and the singularities. Compounding these mysteries is the fact that, while there is no interaction between the conformal field theories, observers from them can fall into the black hole and interact. We address these issues in this paper. In particular, we (i) present a boundary formulation of a class of in-falling bulk observers; (ii) present an argument that a sharp bulk event horizon can only emerge in the infinite $N$ limit of the boundary theory; (iii) give an explicit construction in the boundary theory of an evolution operator for a bulk in-falling observer, making manifest the boundary emergence of the black hole horizons, the interiors, and the associated causal structure. A byproduct is a concept called causal connectability, which is a criterion for any two quantum systems (which do not need to have a known gravity dual) to have an emergent sharp horizon structure.

We discuss the nonlinear corrections entering in the calculation of the primordial black hole abundance from the nonlinear radiation transfer function and the determination of the true physical horizon crossing. We show that the current standard techniques to calculate the abundance of primordial black holes suffer from uncertainties and argue that the primordial black hole abundance may be much smaller than what routinely considered. This would imply, among other consequences, that the interpretation of the recent pulsar timing arrays data from scalar-induced gravitational waves may not be ruled out because of an overproduction of primordial black holes.

We calculate the effect of gravitational lensing on the parity-odd power spectrum of the cosmic microwave background (CMB) polarization induced by axionlike particles (ALPs). Several recent works have reported a tantalizing hint of cosmic birefringence, a rotation of the linear polarization plane of CMB, which ALPs can explain. In future CMB observations, we can measure cosmic birefringence more precisely to get insight into ALPs. We find that the lensing effect is necessary to fit the observed $EB$ power spectrum induced by cosmic birefringence in future CMB observations, including Simons Observatory and CMB-S4. We also show that the estimated ALPs parameters are biased if we ignore the lensing effect. Therefore, the lensing correction to the parity-odd power spectra must be included in future high-resolution CMB experiments.

This article provides the details on the technical derivation of the gravitational waveform and total gravitational-wave energy flux of nonspinning compact binary systems to the fourth post-Newtonian (4PN) order beyond the Einstein quadrupole formula. In particular: (i) we overview the link between the radiative multipole moments measured at infinity and the source moments in the framework of dimensional regularization; (ii) we compute special corrections to the source moments due to “infrared” commutators arising at the 4PN order; (iii) we derive a “postadiabatic” correction needed to evaluate the tail integral with 2.5PN relative precision; (iv) we discuss the relation between the binary’s orbital frequency in quasicircular orbit and the gravitational-wave frequency measured at infinity; (v) we compute the hereditary effects at the 4PN order, including those coming from the recently derived tails-of-memory; and (vi) we describe the various tests we have performed to ensure the correctness of the results. Those results are collected in an ancillary file.

We present evidence for a duality between Jackiw-Teitelboim gravity minimally coupled to a free massive scalar field and a single-trace two-matrix model. One matrix is the Hamiltonian $H$ of a holographic disorder-averaged quantum mechanics, while the other matrix is the light operator $\mathcal{O}$ dual to the bulk scalar field. The single-boundary observables of interest are thermal correlation functions of $\mathcal{O}$. We study the matching of the genus zero-, one- and two-boundary expectation values in the matrix model to the disk and cylinder Euclidean path integrals. The non-Gaussian statistics of the matrix elements of $\mathcal{O}$ correspond to a generalization of the eigenstate thermalization hypothesis ansatz. We describe multiple ways to construct double-scaled matrix models that reproduce the gravitational disk correlators. One method involves imposing an operator equation obeyed by $H$ and $\mathcal{O}$ as a constraint on the two matrices. Separately, we design a model that reproduces certain double-scaled Sachdev-Ye-Kitaev correlators that may be scaled once more to obtain the disk correlators. We show that in any single-trace, two-matrix model, the genus zero two-boundary expectation value, with up to one $\mathcal{O}$ insertion on each boundary, can be computed directly from all of the genus zero one-boundary correlators. Applied to the models of interest, we find that these cylinder observables depend on the details of the double-scaling limit. To the extent we have checked, it is possible to reproduce the gravitational double-trumpet, which is UV divergent, from a systematic classification of matrix model ‘t Hooft diagrams. The UV divergence indicates that the matrix integral saddle of interest is perturbatively unstable. A nonperturbative treatment of the matrix models discussed in this work is left for future investigations.

New light scalar degrees of freedom may alleviate the dark matter and dark energy problems, but if coupled to matter, they generally mediate a fifth force. In order for this fifth force to be consistent with existing constraints, it must be suppressed close to matter sources, e.g. through a nonlinear screening mechanism. In this work, we investigate the nonrelativistic two-body problem in shift-symmetric scalar-tensor theories that exhibit kinetic screening ($k$ mouflage), both numerically and analytically. We develop an approximate scheme, based on a Hodge-Helmholtz decomposition of the Noether current associated to the shift symmetry, allowing for a qualitative insight into the dynamics and yielding results in good agreement with the numerical ones in most of the parameter space. We apply the formalism to polynomial $k$ essence and to Dirac-Born-Infeld type theories, as well as to theories that develop “anti-screening.” In the deep nonlinear regime, we find that the fifth force is screened slightly more efficiently in equal-mass systems than in extreme mass-ratio ones. However, we find that systems with comparable masses also exhibit regions where the screening is ineffective. These descreened spheroidal regions (bubbles) could in principle be probed in the Solar System with sufficiently precise space accelerometers.

We develop a frequency-domain method for calculating the self-force acting on a scalar charge on a fixed scattering geodesic in Schwarzschild spacetime. Existing frequency-domain methods, which are tailored for bound orbits, are inadequate here for several reasons. One must account for the continuous spectrum in the scattering problem, deal with slowly convergent radial integrals that are hard to evaluate numerically, and confront the inapplicability of the standard self-force method of “extended homogeneous solutions,” which only works for compactly supported sources. We tackle each of these issues in turn, and then present a full numerical implementation, in which we calculate the self-force correction to the scatter angle due to scalar-field backreaction. We perform a range of internal validation tests, as well as ones based on comparison with existing time-domain results. We discuss the merits and remaining limitations of our method, and outline directions for future work.

The physical interpretation of the exact solutions of the Einstein field equations is, in general, a challenging task, part of the difficulties lying in the significance of the coordinate system. We discuss the extension of the International Astronomical Union (IAU) reference system to the exact theory. It is seen that such an extension, retaining some of its crucial properties, can be achieved in a special class of spacetimes, admitting nonshearing congruences of observers which, at infinity, have zero vorticity and acceleration. As applications, we consider the Friedmann–Lemaître–Robertson–Walker (FLRW), Kerr and Newman–Unti–Tamburino (NUT) spacetimes, the van Stockum rotating dust cylinder, spinning cosmic strings and, finally, we debunk the so-called Balasin-Grumiller (BG) model, and the claims that the galaxies’ rotation curves can be explained through gravitomagnetic effects without the need for dark matter. The BG spacetime is shown to be completely inappropriate as a galactic model: its dust is actually static with respect to the asymptotic inertial frame, its gravitomagnetic effects arise from unphysical singularities along the axis (a pair of NUT rods, combined with a spinning cosmic string), and the rotation curves obtained are merely down to an invalid choice of reference frame—the congruence of zero angular momentum observers, which are being dragged by the singularities.

The $J/\psi \to {\mathrm{\Xi }}^0{\overline{\mathrm{\Xi }}}^0$ process and subsequent decays are investigated using $(10087\pm 44)\times {10}^{6}J/\psi$ events collected at the BESIII experiment. The decay parameters of ${\mathrm{\Xi }}^0$ and ${\overline{\mathrm{\Xi }}}^0$ are simultaneously measured to be ${\alpha }_{\mathrm{\Xi }}=-0.3750\pm 0.0034\pm 0.0016$, ${\overline{\alpha }}_{\mathrm{\Xi }}=0.3790\pm 0.0034\pm 0.0021$, ${\varphi }_{\mathrm{\Xi }}=0.0051\pm 0.0096\pm 0.0018\mathrm{rad}$, ${\overline{\varphi }}_{\mathrm{\Xi }}=-0.0053\pm 0.0097\pm 0.0019\mathrm{rad}$ with unprecedented accuracies, where the first and the second uncertainties are statistical and systematic, respectively. The most precise values for $CP$ asymmetry observables of ${\mathrm{\Xi }}^0$ decay are obtained to be $A_{CP}^{\mathrm{\Xi }}=(-5.4\pm 6.5\pm 3.1)\times {10}^{-3}$ and $\mathrm{\Delta }{\varphi }_{CP}^{\mathrm{\Xi }}=(-0.1\pm 6.9\pm 0.9)\times {10}^{-3}\mathrm{rad}$. For the first time, the weak and strong phase differences are determined to be ${\xi }_P-{\xi }_S=(0.0\pm 1.7\pm 0.2)\times {10}^{-2}\mathrm{rad}$ and ${\delta }_P-{\delta }_S=(-1.3\pm 1.7\pm 0.4)\times {10}^{-2}\mathrm{rad}$, which are the most precise results for any weakly decaying baryon. These results will play important roles in the studies of the $CP$ violations and polarizations for the strange, charmed, and beauty baryons.

We discuss the structure of nonlocal effective action generating the conformal anomaly in classically Weyl invariant theories in curved spacetime. By the procedure of conformal gauge fixing, selecting the metric representative on a conformal group orbit, we split the renormalized effective action into anomalous and Weyl invariant parts. A wide family of thus obtained anomalous actions is shown to include two special cases of Riegert–Fradkin–Tseytlin and Fradkin–Vilkovisky actions. Both actions are shown to be contained in the first 3 orders of the curvature expansion for a generic one-loop effective action obtained by covariant perturbation theory. The complementary Weyl invariant part of the action is given by the “conformization” of the full effective action—restricting its argument to the conformally invariant representative of the orbit of the conformal group. This is likely to resolve a long-standing debate between the proponents of the Riegert action and adherents of the perturbation expansion for the effective action with typical nonlocal logarithmic form factors. We derive the relation between quantum stress tensors on conformally related metric backgrounds, which generalizes the known Brown-Cassidy equation to the case of nonzero Weyl tensor, and discuss applications of this relation in the cosmological model driven by conformal field theory. We also discuss the issue of renormalization group running for the cosmological and gravitational coupling constants and show that it exhibits a kind of a metamorphosis to the nonlocal form factors of the so-called partners of the cosmological and Einstein terms—nonlocal curvature squared terms of the effective action.

We study the effect of super-sample covariance (SSC) on the power spectrum and higher-order statistics; bispectrum, halo mass function, and void size function. We also investigate the effect of SSC on the cross covariance between the statistics. We consider both the matter and halo fields. Higher-order statistics of the large-scale structure contain additional cosmological information beyond the power spectrum and are a powerful tool to constrain cosmology. They are a promising probe for ongoing and upcoming high-precision cosmological surveys such as DESI, PFS, Rubin Observatory LSST, Euclid, SPHEREx, SKA, and Roman Space Telescope. Cosmological simulations used in modeling and validating these statistics often have sizes that are much smaller than the observed Universe. Density fluctuations on scales larger than the simulation box, known as super-sample modes, are not captured by the simulations and in turn can lead to inaccuracies in the covariance matrix. We compare the covariance measured using simulation boxes containing super-sample modes to those without. We also compare with the separate universe approach. We find that while the power spectrum, bispectrum and halo mass function show significant scale- or mass-dependent SSC, the void size function shows relatively small SSC. We also find significant SSC contributions to the cross covariances between the different statistics, implying that future joint analyses will need to carefully take into consideration the effect of SSC. To enable further study of SSC, our simulations have been made publicly available.

The study of impulsive astrophysical radio emission makes it possible to probe the intervening plasma between the emission source and the Earth. In cold electron-ion plasmas, the circular propagating wave modes primarily alter the linear polarization plane that scales with the inverse-square of the emission frequency. In relativistic plasmas, the wave modes are elliptically polarized, and it is possible to convert linearly polarized emission into circular and vice versa. Fast radio bursts (FRBs) enable the study of not only the electron-ion plasma of the intergalactic medium but potentially the extreme magneto-ionic medium in which these intense pulses are produced. Here we report on the polarimetric analysis of a repeat burst from the FRB 20201124A source. The burst displayed a significant frequency-dependent circularly polarized component, unlike other bursts from this source or any other FRB found to date. We model the frequency dependence of the circular polarization using a phenomenological generalized Faraday rotation framework. We find that the observed circular polarization in the burst can be adequately explained by the propagation of an initially linearly polarized burst signal through a relativistic plasma along the line of sight from the progenitor.

The $B^{+}\to D_s^{+}{D}_s^{-}{K}^{+}$ decay is observed for the first time using proton-proton collision data collected by the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$. Its branching fraction relative to that of the $B^{+}\to D^{+}{D}^{-}{K}^{+}$ decay is measured to be $\frac{\mathcal{B}(B^{+}\to D_s^{+}{D}_s^{-}{K}^{+})}{\mathcal{B}(B^{+}\to D^{+}{D}^{-}{K}^{+})}=0.525\pm 0.033\pm 0.027\pm 0.034,$ where the first uncertainty is statistical, the second systematic, and the third is due to the uncertainties on the branching fractions of the $D_s^{\pm }\to K^{\mp }{K}^{\pm }{\pi }^{\pm }$ and $D^{\pm }\to K^{\mp }{\pi }^{\pm }{\pi }^{\pm }$ decays. This measurement fills an experimental gap in the knowledge of the family of Cabibbo-favored $\overline{b}\to \overline{c}c\overline{s}$ transitions and opens the path for unique studies of spectroscopy in future.

A simultaneous analysis of the $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ and $B^0\to K^{*0}{\ell }^{+}{\ell }^{-}$ decays is performed to test muon-electron universality in two ranges of the square of the dilepton invariant mass, $q^2$. The measurement uses a sample of beauty meson decays produced in proton-proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$. A sequence of multivariate selections and strict particle identification requirements produce a higher signal purity and a better statistical sensitivity per unit luminosity than previous LHCb lepton universality tests using the same decay modes. Residual backgrounds due to misidentified hadronic decays are studied using data and included in the fit model. Each of the four lepton universality measurements reported is either the first in the given $q^2$ interval or supersedes previous LHCb measurements. The results are compatible with the predictions of the Standard Model.

Resonant contributions in $B^0\to \overline{D}{{}^{0}D}_s^{+}{\pi }^{-}$ and $B^{+}\to D^{-}{D}_s^{+}{\pi }^{+}$ decays are determined with an amplitude analysis, which is performed both separately and simultaneously, where in the latter case isospin symmetry between the decays is assumed. The analysis is based on data collected by the LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8, and 13 TeV. The full data sample corresponds to an integrated luminosity of $9{\mathrm{fb}}^{-1}$. A doubly charged spin-0 open-charm tetraquark candidate together with a neutral partner, both with masses near 2.9 GeV, are observed in the $D_s\pi$ decay channel.

The kinematic and thermal Sunyaev-Zel’dovich (kSZ and tSZ) effects probe the abundance and thermodynamics of ionized gas in galaxies and clusters. We present a new hybrid estimator to measure the kSZ effect by combining cosmic microwave background temperature anisotropy maps with photometric and spectroscopic optical survey data. The method interpolates a velocity reconstruction from a spectroscopic catalog at the positions of objects in a photometric catalog, which makes it possible to leverage the high number density of the photometric catalog and the precision of the spectroscopic survey. Combining this hybrid kSZ estimator with a measurement of the tSZ effect simultaneously constrains the density and temperature of free electrons in the photometrically selected galaxies. Using the $1000{\mathrm{deg}}^2$ of overlap between the Atacama Cosmology Telescope (ACT) Data Release 5, the first three years of data from the Dark Energy Survey (DES), and the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, we detect the kSZ signal at $4.8\sigma$ and reject the null (no-kSZ) hypothesis at $5.1\sigma$. This corresponds to $2.0\sigma$ per 100,000 photometric objects with a velocity field based on a spectroscopic survey with $1/5^{\mathrm{th}}$ the density of the photometric catalog. For comparison, a recent ACT analysis using exclusively spectroscopic data from BOSS measured the kSZ signal at $2.1\sigma$ per 100,000 objects. Our derived constraints on the thermodynamic properties of the galaxy halos are consistent with previous measurements. With future surveys, such as the Dark Energy Spectroscopic Instrument and the Rubin Observatory Legacy Survey of Space and Time, we expect that this hybrid estimator could result in measurements with significantly better signal-to-noise than those that rely on spectroscopic data alone.