Matrix models have phase transitions in which distributions of variables change topologically like the Gross-Witten-Wadia transition. In a recent study, similar splitting-merging behavior of distributions of dynamical variables was observed in a tensor-vectors system by numerical simulations. In this paper, we study the system exactly in some large-$N$ limits, in which the distributions are discrete sets of configurations rather than continuous. We find cascades of first-order phase transitions for fixed tensors, and first- and second-order phase transitions for random tensors, being characterized by breaking patterns of replica symmetries. The system is of interest across three different subjects at least: The splitting dynamics plays essential roles in the emergence of classical spacetimes in a tensor model of quantum gravity. The splitting dynamics automatically detects the rank of a tensor in the tensor rank decomposition in data analysis. The system provides a variant of the spherical $p$-spin model for spin glasses with a new nontrivial parameter. We discuss some implications of the results from these perspectives. The results are compared with some numerical simulations to check the large-$N$ convergence and the assumptions made in the analysis.

We investigate several quantum phenomena related to quadratic gravity after rewriting the general fourth-order action in a more convenient form that is second order in derivatives and produces only first-class constraints in phase space. We find that a Higgs mechanism may occur in the conformally invariant subset of the general quadratic action if the theory is conformally coupled to a scalar field that acquires a nonzero vacuum expectation value and spontaneously breaks the conformal symmetry. Then, in the broken phase, the originally massless spin-2 ghost may absorb both the scalar and vector fields to become massive. We also perform a Becchi-Rouet-Stora-Tyutin quantization of second-order quadratic gravity in the covariant operator formalism and discuss conditions under which unitarity of the full interacting quantum theory may be established.

Black holes are well known to be fast scramblers, responsible for physics of quantum chaos in dual holography. Recently, the Euclidean wormhole has been proposed to play a central role in the chaotic behavior of the spectral form factor. Furthermore, this phenomena was reinterpreted based on an effective field theory approach for quantum chaos. Since the graded nonlinear $\sigma$-model approach can describe not only the Wigner-Dyson level statistics but also its Poisson distribution, it is natural to ask whether the dual holography can touch the Poisson regime beyond the quantum chaos. In this study, we investigate disordered strongly coupled conformal field theories in the large central-charge limit. An idea is to consider a quenched average for metric fluctuations and to take into account the renormalization group flow of the metric-tensor distribution function from the UV to the IR boundary. Here, renormalization effects at a given disorder configuration are described by the conventional dual holography. We uncover that the renormalized distribution function shows a power-law behavior universally, interpreted as an infinite randomness fixed point.

We systematically study the top-down model of loop quantum black holes (LQBHs), recently derived by Alesci, Bahrami, and Pranzetti (ABP). Starting from the full theory of loop quantum gravity, ABP constructed a model with respect to coherent states peaked around spherically symmetric geometry, in which both holonomy and inverse volume corrections are taken into account, and shown that the classical singularity used to appear inside the Schwarzschild black hole is replaced by a regular transition surface. To understand the structure of the model, we first derive several well-known LQBH solutions by taking proper limits. These include the Böhmer-Vandersloot and Ashtekar-Olmedo-Singh models, which were all obtained by the so-called bottom-up polymerizations within the framework of the minisuperspace quantizations. Then, we study the ABP model, and find that the inverse volume corrections become important only when the radius of the two-sphere is of the Planck size. For macroscopic black holes, the minimal radius obtained at the transition surface is always much larger than the Planck scale, and hence these corrections are always subleading. The transition surface divides the whole spacetime into two regions, and in one of them the spacetime is asymptotically Schwarzschild-like, while in the other region, the asymptotical behavior sensitively depends on the ratio of two spin numbers involved in the model, and can be divided into three different classes. In one class, the spacetime in the 2-planes orthogonal to the two spheres is asymptotically flat, and in the second one it is not even conformally flat, while in the third one it can be asymptotically conformally flat by properly choosing the free parameters of the model. In the latter, it is asymptotically de Sitter. However, in any of these three classes, sharply in contrast to the models obtained by the bottom-up approach, the spacetime is already geodesically complete, and no additional extensions are needed in both sides of the transition surface. In particular, identical multiple black hole and white hole structures do not exist.

The Teukolsky wave equations governing fields of spin 0, $\frac{1}{2}$, 1, $\frac{3}{2}$, and 2 are generalized to the case of conformally separable solutions for accreting, rotating black holes.

Scattering angles for probes in Kerr metrics are derived for scattering in the equatorial plane of the black hole. We use a method that naturally resums all orders in the spin of the Kerr black hole, thus facilitating comparisons with scattering-angle computations based on the post-Minkowskian expansion from scattering amplitudes or worldline calculations. We extend these results to spinning black-hole probes up to and including second order in the probe spin and any order in the post-Minkowskian expansion for probe spins aligned with the Kerr spin. When truncating to third post-Minkowskian order, our results agree with those obtained by amplitude and worldline methods.

We use the quantum unimodular theory of gravity to relate the value of the cosmological constant, $\mathrm{\Lambda }$, and the energy scale for the emergence of cosmological classicality. The fact that $\mathrm{\Lambda }$ and unimodular time are complementary quantum variables implies a perennially quantum Universe should $\mathrm{\Lambda }$ be zero (or, indeed, fixed at any value). Likewise, the smallness of $\mathrm{\Lambda }$ puts an upper bound on its uncertainty, and thus a lower bound on the unimodular clock’s uncertainty or the cosmic time for the emergence of classicality. Far from being the Planck scale, classicality arises at around $7\times {10}^{11}\mathrm{GeV}$ for the observed $\mathrm{\Lambda }$, and taking the region of classicality to be our Hubble volume. We confirm this argument with a direct evaluation of the wave function of the Universe in the connection representation for unimodular theory. Our argument is robust, with the only leeway being in the comoving volume of our cosmological classical patch, which should be bigger than that of the observed last scattering surface. Should it be taken to be the whole of a closed Universe, then the constraint depends weakly on ${\mathrm{\Omega }}_k$: for $-{\mathrm{\Omega }}_k<{10}^{-3}$, classicality is reached at $>4\times {10}^{12}\mathrm{GeV}$. If it is infinite, then this energy scale is infinite, and the Universe is always classical within the minisuperspace approximation. It is a remarkable coincidence that the only way to render the Universe classical just below the Planck scale is to define the size of the classical patch as the scale of nonlinearity for a red spectrum with the observed spectral index $n_s=0.967(4)$ (about ${10}^{11}$ times the size of the current Hubble volume). In the context of holographic cosmology, we may interpret this size as the scale of confinement in the dual 3D quantum field theory, which may be probed (directly or indirectly) with future cosmological surveys.

We present the first detailed analysis of the connection between galaxies and their dark matter halos for the unWISE galaxy catalog—a full-sky, infrared-selected sample built from WISE data, containing over 500 million galaxies. Using unWISE galaxy-galaxy autocorrelation and Planck CMB lensing-galaxy cross-correlation measurements down to 10 arcmin angular scales, we constrain the halo occupation distribution (HOD), a model describing how central and satellite galaxies are distributed within dark matter halos, for three unWISE galaxy samples at mean redshifts $\overline{z}\approx 0.6$, 1.1, and 1.5, assuming a fixed cosmology at the best-fit Planck $\mathrm{\Lambda }\mathrm{CDM}$ values. We constrain the characteristic minimum halo mass to host a central galaxy, $M_{\min }^{\mathrm{HOD}}=1.83_{-1.63}^{+0.41}\times {10}^{12}{M}_{\odot }/h$, ${5.22}_{-4.80}^{+0.34}\times {10}^{12}{M}_{\odot }/h$, ${6.60}_{-1.11}^{+0.30}\times {10}^{13}{M}_{\odot }/h$ and the mass scale at which one satellite galaxy per halo is found, $M_1^{\prime }=1.13_{-0.70}^{+0.32}\times {10}^{13}{M}_{\odot }/h$, ${1.18}_{-1.11}^{+0.30}\times {10}^{13}{M}_{\odot }/h$, ${1.23}_{-1.17}^{+0.14}\times {10}^{14}{M}_{\odot }/h$ for the unWISE samples at $\overline{z}\approx 0.6$, 1.1, and 1.5, respectively. We find that all three samples are dominated by central galaxies, rather than satellites. Using our constrained HOD models, we infer the effective linear galaxy bias for each unWISE sample, and find that it does not evolve as steeply with redshift as found in previous perturbation-theory-based analyses of these galaxies. We discuss possible sources of systematic uncertainty in our results, the most significant of which is the uncertainty on the galaxy redshift distribution. Our HOD constraints provide a detailed, quantitative understanding of how the unWISE galaxies populate the underlying dark matter halo distribution. These constraints will have a direct impact on future studies employing the unWISE galaxies as a cosmological and astrophysical probe, including measurements of ionized gas thermodynamics and dark matter profiles via Sunyaev-Zel’dovich and lensing cross-correlations.

The existence of self-similar solutions is discussed in symmetric teleparallel $f(Q)$ theory for a Friedmann-Lemaître-Robertson-Walker background geometry with zero and nonzero spatial curvature. For the four distinct families of connections that describe the specific cosmology in symmetric teleparallel gravity, the functional form of $f(Q)$ is reconstructed. Finally, to see if the analogy with GR holds, we discuss the relation of the self-similar solutions with the asymptotic behavior of more general $f(Q)$ functions.

We discuss the formation of cosmic strings or macroscopic color flux tubes at the phase transition from the deconfinement to confinement phase in pure Yang–Mills (YM) theory, such as $\mathrm{SU}(N)$, $\mathrm{Sp}(N)$, $\mathrm{SO}(N)$, and $\text{Spin}(N)$, based on the current understanding of theoretical physics. According to the holographic dual descriptions, the cosmic strings are dual to fundamental strings or wrapped D-branes in the gravity side depending on the structure of the gauge group, and the reconnection probability is suppressed by $\mathcal{O}(N^{-2})$ and $e^{-\mathcal{O}(N)}$, respectively. The pure YM theory thus provides a simple realization of cosmic F- and D-strings without the need for a brane-inflationary scenario or extra dimension. We also review the stability of cosmic strings based on the concept of 1-form symmetry, which further implies the existence of a baryon vertex in some YM theory. We calculate the gravitational wave spectrum that is emitted from the cosmic strings based on an extended velocity-dependent one-scale model and discuss its detectability based on ongoing and planned gravitational-wave experiments. In particular, the SKA and LISA can observe gravitational signals if the confinement scale is higher than $\mathcal{O}({10}^{12})\mathrm{GeV}$ and $\mathcal{O}({10}^{10})\mathrm{GeV}$ for $\mathrm{SU}(N)$ with $N=\mathcal{O}(1)$, respectively.

This paper contains a detailed study of the properties of a simple model attempting to explain dark energy as originated from quantum fluctuations of a light spectator scalar field in inflation. In Belgacem and Prokopec [Phys. Lett. B 831, 137174 (2022)] we recently outlined how Starobinsky’s stochastic formalism can be used to study the spatial correlations imprinted on dark energy by its quantum origin in this model and we studied their possible role in relieving the Hubble tension. Here we provide a more comprehensive derivation of the results in Belgacem and Prokopec and we refine some of our estimates, comparing to the approximate results obtained previously. Among the main results, we analyze the noncoincident correlators predicted by a full field theoretical treatment and their relation with those computed within the stochastic formalism. We find that in the region where stochastic theory predicts significant sub-Hubble correlators it is in disagreement with field theoretical predictions. However, agreement can be restored by introducing a reduced speed of sound for the scalar field. We also discuss an alternative approach to the problem of studying correlators within the stochastic formalism based directly on the evolution of probability distributions. We find that the two approaches give the same answer for 2-point functions of the field, but not for 4-point functions relevant to density correlators and we discuss the behavior of the two methods with respect to Wick’s theorem.

The intrinsic alignment (IA) of galaxies is potentially a major limitation in deriving cosmological constraints from weak lensing surveys. In order to investigate this effect, we assign intrinsic shapes and orientations to galaxies in the light-cone output of the MICE simulation, spanning $\sim 5000{\mathrm{deg}}^2$ and reaching redshift $z=1.4$. This assignment is based on a semianalytic IA model that uses photometric properties of galaxies as well as the spin and shape of their host halos. Advancing on previous work, we include more realistic distributions of galaxy shapes and a luminosity-dependent galaxy-halo alignment. The IA model parameters are calibrated against COSMOS and BOSS LOWZ observations. The null detection of IA in observations of blue galaxies is accounted for by setting random orientations for these objects. We compare the two-point alignment statistics measured in the simulation against predictions from the analytical IA models NLA and TATT over a wide range of scales, redshifts, and luminosities for red and blue galaxies separately. We find that both models fit the measurements well at scales above $8h^{-1}\mathrm{Mpc}$, while TATT outperforms NLA at smaller scales. The IA parameters derived from our fits are in broad agreement with various observational constraints from red galaxies. Lastly, we build a realistic source sample, mimicking DES Year 3 observations and use it to predict the IA contamination to the observed shear statistics. We find this prediction to be within the measurement uncertainty, which might be a consequence of the random alignment of blue galaxies in the simulation.

We combine a recent construction of a Becchi-Rouet-Stora-Tyutin (BRST)-invariant, nonlinear massive gauge fixing with the background field formalism. The resulting generating functional preserves background-field invariance as well as BRST invariance of the quantum field manifestly. The construction features BRST-invariant mass parameters for the quantum gauge and ghost fields. The formalism employs a background Nakanishi-Lautrup field which is part of the nonlinear gauge-fixing sector and thus should not affect observables. We verify this expectation by computing the one-loop effective action and the beta function of the gauge coupling as an example. The corresponding Schwinger functional generating connected correlation functions acquires additional one-particle reducible terms that vanish on shell. We also study off-shell one-loop contributions in order to explore the consequences of a nonlinear gauge fixing scheme involving a background Nakanishi-Lautrup field. As an application, we show that our formalism straightforwardly accommodates nonperturbative information about propagators in the Landau gauge in the form of the so-called decoupling solution. Using this nonperturbative input, we find evidence for the formation of a gluon condensate for sufficiently large coupling, whose scale is set by the BRST-invariant gluon mass parameter.

New vectorlike quarks are predicted in many new physics scenarios beyond the Standard Model (SM) and could potentially be discovered at the LHC. Based on a simplified model including a singlet vectorlike top partner with charge $2/3$, we investigate the process $pp\to TT$ via a $t$ channel induced by the couplings between the top partner with the first-generation SM quarks. We calculate the production cross section and further study the observability of the heavy top partner in the channel $T\to Wq$ at the high-luminosity LHC (HL-LHC) using final states with same-sign dileptons (electrons or muons), two jets, and missing transverse momentum. At the 14 TeV LHC with an integrated luminosity of $3000{\mathrm{fb}}^{-1}$, the $2\sigma$ exclusion limits, as well as the $5\sigma$ discovery reach in the parameter plane of the two variables $g^{*}-R_L$, are respectively obtained at the HL-LHC. We also obtain the $2\sigma$ exclusion limit on the coupling strength parameter $g^{*}$ in the case in which the vectorlike top partner is coupled only to the first-generation quarks.

While most searches for cosmic axions so far focused on their cold relics as (a component of) dark matter, various well-motivated cosmological sources can produce “boosted” axions that remain relativistic today. We demonstrate that existing/upcoming neutrino experiments such as Super-Kamiokande, Hyper-Kamiokande, DUNE, JUNO, and IceCube can probe such energetic axion relics. The characteristic signature is the monoenergetic single photon signal from axion absorption induced by the axion-photon coupling. This proposal offers to cover parameter ranges complementary to existing axion searches and provides new opportunities for discovery with neutrino facilities.

We study exotic Higgs decays $h\to ZX$, with $X$ an invisible beyond the Standard Model (SM) particle, resulting in a semidark final state. Such exotic Higgs decays may occur in theories of axionlike particles (ALPs), dark photons or pseudoscalar mediators between the SM and dark matter. The SM process $h\to Z\nu \overline{\nu }$ represents an irreducible “neutrino floor” background to these new physics searches, providing also a target experimental sensitivity for them. We analyze $h\to Z+\mathrm{invisible}$ searches at the LHC and a future ILC, showing that these exotic Higgs decays can yield sensitivity to unexplored regions of parameter space for ALPs and dark matter models.

We study the nature of the phase transition of lattice gauge theories at high temperature and high density by focusing on the probability distribution function, which represents the probability that a certain density will be realized in a heat bath. The probability distribution function is obtained by creating a canonical partition function fixing the number of particles from the grand partition function. However, if the $Z_3$ center symmetry, which is important for understanding the finite temperature phase transition of $SU(3)$ lattice gauge theory, is maintained on a finite lattice, the probability distribution function is always zero, except when the number of particles is a multiple of three. For $U(1)$ lattice gauge theory, this problem is more serious. The probability distribution becomes zero when the particle number is nonzero. This problem is essentially the same as the problem that the expectation value of the Polyakov loop is always zero when calculating with finite volume. In this study, we propose a solution to this problem. We also propose a method to avoid the sign problem, which is an important problem at finite density, using the center symmetry. In the case of $U(1)$ lattice gauge theory with heavy fermions, numerical simulations are actually performed, and we demonstrate that the probability distribution function at a finite density can be calculated by the method proposed in this study. Furthermore, the application of this method to QCD is discussed.

The advantage of simulating lattice field theory with quantum computers is hamstrung by the limited resources that induce large errors from finite volume and sizable lattice spacings. Previous work has shown how classical simulations near the Hamiltonian limit can be used for setting the lattice spacings in real time through analytical continuation, thereby reducing errors in quantum simulations. In this work, we derive perturbative relations between bare and renormalized quantities in Euclidean spacetime at any anisotropy factor—the ratio of spatial to temporal lattice spacings—and in any spatial dimension for $U(N)$ and $SU(N)$. This reduces the required classical preprocessing for quantum simulations. We find less than 10% discrepancy between our perturbative results and those from existing nonperturbative determinations of the anisotropy for $SU(2)$ and $U(1)$ gauge theories. For the discrete groups ${\mathbb{Z}}_{10}$, ${\mathbb{Z}}_{100}$ and $\mathbb{B}\mathbb{I}$, we perform lattice Monte Carlo simulations to extract anisotropy factors and observe similar agreement with our perturbative results.

Inspired by the center-vortex dominance in the infrared sector of $SU(N)$ Yang-Mills theory observed on the lattice, we propose a vacuum wave functional localized on an ensemble of correlated center vortices endowed with stiffness and magnetic monopoles that change the orientation of the vortex flux. In the electric-field representation, this wave functional becomes an effective partition function for N complex scalar fields. The inclusion of both oriented and nonoriented vortices as well as so-called N-vortex matchings leads to an effective potential that has only a center symmetry left. In the center-vortex condensed phase, this symmetry is spontaneously broken. In this case, the Wilson loop average can be approximated by a solitonic saddle point localized around the minimal surface. The asymptotic string tension thus obtained displays Casimir scaling.

We use a $\mathcal{O}({\alpha }_s,{\mathrm{\Lambda }}_{\mathrm{QCD}}/m_c)$ heavy quark effective theory scheme, where only $\mathcal{O}({\mathrm{\Lambda }}_{\mathrm{QCD}}/m_b)$ corrections are neglected, to study the matrix elements of the scalar, pseudoscalar, vector, axial-vector and tensor currents between the ${\mathrm{\Lambda }}_b$ ground state and the odd parity charm ${\mathrm{\Lambda }}_c(2595{)}^{+}$ and ${\mathrm{\Lambda }}_c(2625{)}^{+}$ resonances. We show that in the near-zero recoil regime, the scheme describes reasonably well, taking into account uncertainties, the results for the 24 form factors obtained in lattice QCD (LQCD) just in terms of only four Isgur-Wise (IW) functions. We also find some support for the possibility that the ${\mathrm{\Lambda }}_c(2595{)}^{+}$ and ${\mathrm{\Lambda }}_c(2625{)}^{+}$ resonances might form a heavy quark spin symmetry (HQSS) doublet. However, we argue that the available LQCD description of these two resonances is not accurate enough to disentangle the possible effects of the ${\mathrm{\Sigma }}_c\pi$ and ${\mathrm{\Sigma }}_c^{*}\pi$ thresholds, located only a few MeV above their position, and that it cannot be ruled out that these states are not HQSS partners. Finally, we study the ratio $\frac{d\mathrm{\Gamma }[{\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_{c,1/2^{-}}^{*}\ell {\overline{\nu }}_{\ell }]/d{q}^2}{d\mathrm{\Gamma }[{\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_{c,3/2^{-}}^{*}\ell {\overline{\nu }}_{\ell }]/d{q}^2}$ of the Standard Model differential semileptonic decay widths, with $q$ the four-momentum transferred between the initial and final hadrons. We provide a natural explanation for the existence of large deviations, near the zero recoil, of this ratio from $1/2$ (value predicted in the infinite heavy quark mass limit, assuming that the ${\mathrm{\Lambda }}_{c,1/2^{-}}^{*}$ and ${\mathrm{\Lambda }}_{c,3/2^{-}}^{*}$ are the two members of a HQSS doublet) based on S-wave contributions to the ${\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_{c,1/2^{-}}^{*}$ decay amplitude driven by a subleading IW function.