We determine the complete space-time metric from the bootstrapped Newtonian potential generated by a static spherically symmetric source in the surrounding vacuum. This metric contains post-Newtonian parameters which can be further used to constrain the underlying dynamical theory and quantum state of gravity. For values of the post-Newtonian parameters within experimental bounds, the reconstructed metric appears very close to the Schwarzschild solution of general relativity in the whole region outside the event horizon. The latter is however larger in size for the same value of the mass compared to the Schwarzschild case.

Fast pairwise conversions of neutrinos may affect the flavor distribution in the core of neutrino-dense sources. We explore the interplay between collisions and fast conversions within a simplified framework that assumes angle-independent, direction-changing collisions in a neutrino gas that has no spatial inhomogeneity. Counter to expectations, we find that collisions may enhance fast flavor conversions instead of damping them. Our work highlights the need to take into account the feedback of collisions on the neutrino angular distributions self-consistently, in order to predict the flavor outcome in the context of fast pairwise conversions reliably.

We investigate the impact of the nonzero neutrino splitting and elastic neutrino-nucleon collisions on fast neutrino oscillations. Our calculations confirm that a small neutrino mass splitting and the neutrino mass hierarchy have very little effect on fast oscillation waves. We also demonstrate explicitly that fast oscillations remain largely unaffected for the time/distance scales that are much smaller than the neutrino mean free path but are damped on larger scales. This damping originates from both the direct modification of the dispersion relation of the oscillation waves in the neutrino medium and the flattening of the neutrino angular distributions over time. Our work suggests that fast neutrino oscillation waves produced near the neutrino sphere can propagate essentially unimpeded which may have ramifications in various aspects of the supernova physics.

Composite Higgs models can be extended to the Planck scale by means of the partially unified partial compositeness (PUPC) framework. We present in detail the Techni-Pati-Salam model, based on a renormalizable gauge theory $SU(8{)}_{PS}\times SU(2{)}_L\times SU(2{)}_R$. We demonstrate that masses and mixings for all generations of standard model fermions can be obtained via partial compositeness at low energy, with four-fermion operators mediated by either heavy gauge bosons or scalars. The strong dynamics is predicted to be that of a confining $Sp(4{)}_{\mathrm{HC}}$ gauge group, with hyperfermions in the fundamental and two-index antisymmetric representations, with fixed multiplicities. This is motivation for lattice studies of the infrared near-conformal walking phase, with results that may validate or rule out the model. This is the first complete and realistic attempt at providing an ultraviolet completion for composite Higgs models with top partial compositeness. In the baryon-number conserving vacuum, the theory also predicts a dark matter candidate, with a mass in the few TeV range, protected by semi-integer baryon number.

Quark-hadron continuity with two-flavor quarks that was proposed recently connects hadronic matter with neutron ${}^3{P}_2$ superfluidity and two-flavor dense quark matter. This two-flavor dense quark phase consists of the coexistence of the 2SC condensates and the $P$-wave diquark condensates of $d$-quarks, which gives rise to color superconductivity as well as superfluidity. We classify vortices in this phase. The most stable vortices are what we call the non-Abelian Alice strings, which are superfluid vortices with non-Abelian color magnetic fluxes therein, exhibiting so-called topological obstruction, or a non-Abelian generalization of the Alice property. We show that a single Abelian superfluid vortex is unstable against decay into three non-Abelian Alice strings. We discover that a non-Abelian Alice string carries orientational moduli of the real projective space $\mathbb{R}{P}^2$ corresponding to the color flux therein in the presence of the $P$-wave condensates alone. We calculate Aharanov-Bohm (AB) phases around the non-Abelian Alice string, and find that the 2SC condensates and string’s orientational moduli must be aligned with each other because of single-valuedness of the AB phases of the 2SC condensates.

By using the quark part of the energy-momentum tensor current, the gravitational formfactors of the $\rho$, $\pi$, and $K$ mesons are calculated within the light-cone sum rules method. In the considered version, the energy-momentum tensor current is not conserved and as a result, for integer spin $J$, there appear $4J+2$ ($2J+1$) formfactors, which correspond to the conservation (nonconservation) of the energy-momentum tensor current. The average mass radius of $\rho$, $\pi$, and $K$ mesons as well as the gravitational quadrupole moment of the $\rho$ meson are calculated. We also compare our results with the one existing in the literature on these quantities.

Within the framework of the generalized QCD factorization formalism, a set of nuclear-dependent observables all arise from the quark-gluon and gluon-gluon correlation functions, which are closely connected to the well-known jet transport coefficient ($\widehat{q}$) for the nucleus. In this paper, we perform the first global analysis of $\widehat{q}$ for cold nuclear matter with a kinematics dependent parametrization. The analysis takes into account the world data on transverse momentum broadening in semi-inclusive electron-nucleus deep inelastic scattering, Drell-Yan dilepton and heavy quarkonium production in proton-nucleus collisions, as well as the nuclear modification of the structure functions in deep inelastic scattering, comprising a total of 215 data points from 8 datasets. Within our scheme, we clarify quantitatively the universality and kinematics dependence of the nuclear medium property as encoded in $\widehat{q}$. We expect that the determined parametrization of $\widehat{q}$ in cold nuclear matter will have significant impact on precise identification of the transport property of hot dense medium created in heavy ion collisions.

We reply to the comment by Heesen and Brüggen. While we acknowledge the merit of their criticism, we argue that the limits obtained by our method are still valid, within our assumption. All the involved uncertainties should be addressed in depth in order to determine how they affect our limits.

In their recent paper, Chan and Lee discuss an interesting possibility: radio continuum emission from a dwarf irregular galaxy may be used to constrain upper limits on the cross section of annihilating dark matter. They claim that the contributions from nonthermal and thermal emission can be estimated with such accuracy that one can place new upper limits on the annihilation cross section. We argue that the observations presented can be explained entirely with a standard spectrum and no contribution from dark matter. As a result, the estimated upper limits of Chan and Lee are at least by a factor of 100 too low.

In this paper we construct time-dependent solutions of three-dimensional gravity in anti–de Sitter space dual to systems with boundaries (BCFTs), following the AdS/BCFT prescription. Such solutions can be discussed in the context of the dynamics of first-order phase transitions, or more generally, in the description of quantum quenches. As an example, we apply the holographic model to calculate the dynamics of the entanglement entropy of a local quench corresponding to a nucleation of a Euclidean bubble. As in the known $1+1$ conformal field theory examples of local cut and glue quenches, the holographic entanglement entropy grows logarithmically with time with the correct universal coefficient. However, in the bubble quench, the behavior is different at late times. The AdS/BCFT model exhibits the light-cone spreading of correlations and saturation at late times. We also find an analytical formula for the entropy at finite temperature. In the latter case, the initial logarithmic growth is followed by the linear law at intermediate times.

Euclidean wormholes—geometries which connect disconnected boundaries—present a challenge to a standard quantum mechanical interpretation of the theory. One potential resolution is that the gravitational path integral computes the ensemble average of many theories. The connected topologies contribute to the simplest possible observable: the free energy, which is computed using a replica trick. This is distinct from the replica trick used to compute entanglement entropies and appears in the computation of any extensive quantity. We argue that both JT gravity and a simplified version of CGHS admit a regime where the contribution of connected replica wormholes to the free energy is larger than that of disconnected topologies. In both theories we find evidence of replica symmetry breaking, which is reminiscent of the behavior of certain spin glasses. We discuss possible insights about ensemble averaging in gravity from this perspective.

In this paper we derive black hole solutions and thermodynamics in the infinite derivative theory of gravity that is quadratic in curvature. The higher-derivative terms in the action bring about corrections to both the original Schwarzschild black hole metric and the corresponding black hole temperature and entropy, while the topology of the black hole remains the same.

Gravitational waves from binary neutron star inspirals have been detected along with the electromagnetic transients coming from the aftermath of the merger in GW170817. However, much is still unknown about the postmerger dynamics that connects these two sets of observables. This includes if, and when, the postmerger remnant star collapses to a black hole, and what are the necessary conditions to power a short gamma-ray burst and other observed electromagnetic counterparts. Observing the collapse of the postmerger neutron star would shed light on these questions, constraining models for the short gamma-ray burst engine and the hot neutron star equation of state. In this work, we explore the scope of using gravitational wave detectors to measure the timing of the collapse either indirectly, by establishing the shutoff of the postmerger gravitational emission, or—more challengingly—directly, by detecting the collapse signal. For the indirect approach, we consider a kilohertz high-frequency detector design that utilizes a previously studied coupled arm cavity and signal recycling cavity resonance. This design would give a signal-to-noise ratio of 0.5–8.6 (depending on the variation of waveform parameters) for a collapse gravitational wave signal occurring at 10 ms postmerger of a binary at 50 Mpc and with total mass $2.7M_{\odot }$. This detector design is limited by quantum shot noise and the signal-to-noise ratio largely depends on the detector power, which is adopted as 4 MW in this work. For the direct approach, we propose a narrow band detector design, utilizing the sensitivity around the frequency of the arm cavity free spectral range. To attain the maximal achievable quantum sensitivity, which is fundamentally limited by optical loss, we suggest the application of an optomechanical filter cavity that converts the signal recycling cavity into a signal amplifier. The proposed detector achieves a signal-to-noise ratio of 0.3–1.9, independent of the collapse time. This detector is limited by both the fundamental classical and quantum noise with the arm cavity power chosen as 10 MW.

Investigation of quasibound states of black holes is significant for expected ultralight particles, as well as black holes through gravitational waves. We first investigate quasibound states of a massive scalar field for dilatonic charged black holes via numerical analysis. We study the complex eigenfrequencies of the massive scalar field in a wide range of gravitational fine structure constant $\mu M$ in detail, and show the effects of charge. Further, we study the eigenfrequencies of the massive field through an analytical approach by matching the near horizon solution and far field solution, and find its spectra for excited states by the iteration method. We demonstrate that the numerical solution and analytical solution perfectly agree with each other in the region where charge of the black hole is large, both for real and imaginary parts of the eigenfrequencies.

We present a consistent and complete description of the coupling to matter in the Teleparallel Equivalent to General Relativity (TEGR) theory built from a Cartan connection, as we proposed in previous works. A first theorem allows us to obtain parallel transport from the Cartan connection into a proper Ehresmann connection, while a second ensures to link the TEGR-Cartan connection to the Ehresmann one-form that contains the Levi-Civita connection. This yields a coupling to matter in agreement with observations and the Equivalence Principle. As the fundamental fields proceed from the Cartan connection, if one insists on interpreting TEGR as a gauge theory of translations, such translation gauge field can be extracted from the consistent theory presented. However, this would entail a fundamental change in the structures known for gauge theory and a split between gauge field and connection is imperative. The willingness to take such a step is left to the reader.

Possible interactions of dark matter (DM) with Standard Model (SM) particles can be tested with spectral distortions (SDs) of the cosmic microwave background (CMB). In particular, a nonrelativistic DM particle that scatters elastically with photons, electrons, or nuclei imprints a negative chemical potential $\mu$ to the CMB spectrum. This article revisits the first study of this effect, with an accurate treatment of heat exchange between DM and SM particles. We show that the instantaneous-decoupling approximation made in the original study systematically and significantly underestimates the amplitude of SDs. As a consequence, we derive tighter upper bounds to the DM-SM elastic-scattering cross section for DM masses $m_{\chi }\lesssim 0.1\mathrm{MeV}$, from the nondetection of $\mu$-distortions by FIRAS. We also show that a future instrument like PIXIE, sensitive to $|\mu |\sim {10}^{-8}$, would be able to probe DM-SM cross sections much smaller than first forecasted, and orders of magnitude below current upper limits from CMB-anisotropy data, up to DM masses of $\sim 1\mathrm{GeV}$. Lastly, we study the sensitivity of SDs to the electric and magnetic dipole moments of the DM. Although SDs can place nontrivial constraints on these models, we find that even future SD experiments are unlikely to improve upon the best current bounds. This article is accompanied by the public code dmdist, which allows one to compute CMB SDs for generic particle-DM models, specified by their cross sections for elastic scattering with and annihilation into SM particles.

We introduce a very early universe model based on the thermodynamics of a gas of closed strings in a background that is nonperturbative in ${\alpha }^{\prime }$. Upon considering the fully ${\alpha }^{\prime }$-corrected equations extended to include certain anisotropic cosmological backgrounds, we describe the evolution of the system in three different stages parametrized by the gas’s equation of state. Using standard string thermodynamical arguments, we start with an isotropic ten-dimensional universe inside the string scale and evolve it toward a universe with four large spacetime dimensions and six stabilized internal dimensions in the Einstein frame.

Accurate constraints on curvature provide a powerful probe of inflation. However, curvature constraints based on specific assumptions of dark energy may lead to unreliable conclusions when used to test inflation models. To avoid this, it is important to obtain constraints that are independent on assumptions for dark energy. In this paper, we investigate such constraints on curvature from the geometrical probe constructed from galaxy-lensing cross-correlations. We study comprehensively the cross-correlations of galaxy with magnification, measured from type Ia supernovae’s brightnesses (“$g{\kappa }^{\mathrm{SN}}$”), with shear (“$g{\kappa }^{\mathrm{g}}$”), and with CMB lensing (“$g{\kappa }^{\mathrm{CMB}}$”). We find for the LSST and Stage IV CMB surveys, “$g{\kappa }^{\mathrm{SN}}$”, “$g{\kappa }^{\mathrm{g}}$” and “$g{\kappa }^{\mathrm{CMB}}$” can be detected with signal-to-noise ratio $S/N=104$, 2291, 1842 respectively. When combined with supernovae Hubble diagram (“SN”) to constrain curvature, we find galaxy-lensing cross-correlation becomes increasingly important with more degrees of freedom allowed in dark energy. Without any priors, we obtain error on ${\mathrm{\Omega }}_K$ of 0.723 from “$\mathrm{SN}+g{\kappa }^{\mathrm{SN}}$”, 0.0417 from “$\mathrm{SN}+g{\kappa }^{\mathrm{g}}$”, and 0.04 from “$\mathrm{SN}+g{\kappa }^{\mathrm{g}}+g{\kappa }^{\mathrm{CMB}}$” for the LSST and Stage IV CMB surveys. The last one is more competitive than a Stage IV BAO survey (“BAO”). When galaxy-lensing cross-correlations are added to the combined probe of “$\mathrm{SN}+\mathrm{BAO}+\mathrm{CMB}$”, where “CMB” stands for Planck measurement for the CMB acoustic scale, we obtain constraint on ${\mathrm{\Omega }}_K$ of 0.0013, which is a factor of 7 improvement from “$\mathrm{SN}+\mathrm{BAO}+\mathrm{CMB}$”. We study improvements in these results from increasing the high redshift extension of supernovae.

We develop an analytic model to quantitatively describe the evolution of superconducting cosmic string networks. Specifically, we extend the velocity-dependent one-scale (VOS) model to incorporate arbitrary currents and charges on cosmic string world sheets under two main assumptions, the validity of which we also discuss. We derive equations that describe the string network evolution in terms of four macroscopic parameters: the mean string separation (or, alternatively, the string correlation length) and the root mean square velocity which are the cornerstones of the VOS model, together with parameters describing the averaged timelike and spacelike current contributions. We show that our extended description reproduces the particular cases of wiggly and chiral cosmic strings, previously studied in the literature. This VOS model enables investigation of the evolution and possible observational signatures of superconducting cosmic string networks for more general equations of state, and these opportunities will be exploited in a companion paper.

The quantum origin of cosmological primordial perturbations is a cornerstone framework in the interplay between gravity and quantum physics. In this paper, we study the mutual information between two spatial regions in a radiation-dominated universe filled by a curvature perturbation field in a squeezed state. We find an enhancement with respect to the usual mutual information of the Minkowski vacuum due to momentum modes affected by particle production during inflation. This result supports our previous claim of the existence of long-range correlations between primordial black holes (PBH) at formation during the radiation era.