We study magnetotransport in a holographic model where ModMax nonlinear electrodynamics is coupled to Einstein anti–de Sitter gravity. To incorporate momentum relaxation, we introduce spatially linear free scalar fields that break translational symmetry, resulting in an anisotropic medium. Using linear response theory, we compute the DC conductivity matrix in the presence of an external magnetic field, expressing the conductivities in terms of horizon data. Our results demonstrate how the nonlinear ModMax parameter modifies charge transport, particularly influencing the Hall angle and Nernst signal. The nonlinear corrections introduce distinct deviations in both longitudinal and Hall conductivities while preserving the characteristic temperature scaling of strange metals, offering new insights into strongly coupled systems with nonlinear electromagnetic interactions. Notably, the Nernst signal reproduces that of high-$T_c$ cuprate superconductors showing a superconducting dome and a normal phase, with the ModMax deformation parameter tuning critical and onset temperatures. In the strongly nonlinear regime, we find evidence of an exotic state dominated by quasiparticle excitations in the dual material.

We compute the two-point correlation function of the area operator for semiclassical states of loop quantum gravity in the limit of large spins. The cases of intrinsic and extrinsic coherent states are considered, along with a new class of semiclassical states constructed as perturbations of Livine-Speziale coherent states. For the usual coherent states, the correlations are shown to be short-ranged, decaying exponentially with the distance. Introducing perturbations given by correlated elementary excitations and decays of the gravitational field along pairs of loops, we obtain new states that, while preserving the peakedness properties of the unperturbed states, can also display long-ranged correlations. The perturbed coherent states include examples reproducing the typical decay of correlations for quantum fluctuations of the geometry associated with free gravitons on a background metric. Such a behavior is a natural requirement for the compatibility of semiclassical states in quantum gravity with the physical regime pictured by perturbative quantum gravity.

This work develops our previous study of confined phases at finite densities in AdS/QCD by systematically exploring the possibility of baryonic condensates. Using phenomenologically motivated boundary conditions in an AdS hardwall model, we show that both baryonic and quark-type condensates dominate the phase diagram at low temperatures. We also undertake a careful scan of the parameter space to extract robust conclusions.

We show that the energy of a Kaluza-Klein bubble of nothing is unbounded from below even if the size of the circle at infinity and the size of the minimal sphere at the bubble are fixed. We demonstrate this by presenting a family of explicit time-symmetric initial data satisfying these boundary conditions with arbitrarily negative energy. In particular, this is true for very small bubbles, indicating that the standard Kaluza-Klein vacuum is more unstable than previously thought.

An operator-algebraic framework based on Tomita-Takesaki modular theory is used to study aspects of quantum entanglement via the application of the modular conjugation operator $J$. The entanglement structure of quantum fields is studied through the protocol of entanglement harvesting whereby quantum correlations evolve through the time evolution of qubit detectors coupled to a Bosonic field. Modular conjugation operators are constructed for Unruh-Dewitt type qubits interacting with a scalar field such that initially unentangled qubits become entangled. The entanglement harvested in this process is directly quantified by an expectation value involving $J$ offering a physical application of this operator. The modular operator formalism is then extended to the Markovian open system dynamics of coupled qubits by expressing entanglement monotones as functionals of a state $\rho$ and its modular reflection $J\rho J$. The second derivative of such functionals with respect to an external coupling parameter, termed the curvature of entanglement, provides a natural measure of entanglement sensitivity. At points of modular self-duality, the curvature of entanglement coincides with the quantum Fisher information measure. These results demonstrate that the modular conjugation operator $J$ captures both the harvesting of entanglement from quantum fields and the curvature of entanglement in coupled qubit dynamics providing parallel modular structures that connect these systems.

We investigate tidal heating associated with the binary inspiral of strange quark stars and its impact on the resulting gravitational wave signal. Tidal heating during the merger of neutron stars composed of nuclear matter may be considered negligible, but it has been demonstrated recently that the presence of hyperons at high densities could significantly enhance the dissipation during inspiral. In this work, we evaluate the bulk viscosity arising from nonleptonic weak processes involving quarks and show that it can be several orders of magnitude higher than the viscosity of nuclear matter at temperatures relevant to the inspiral phase of the merger of strange stars. We model strange quark matter in the normal phase using a nonideal bag model including electrons and ensure compatibility with astrophysical constraints. By analyzing equal-mass binary systems with component masses ranging from 1.4 to $1.8M_{\odot }$, we find that temperatures close to 0.1 MeV are reached by the end of the inspiral phase. We also estimate the effect on the gravitational waveform and conclude that the additional phase shift could range from 0.1 to 0.5 radians for strange quark masses of 200 MeV, making it potentially detectable by next-generation gravitational wave detectors. Given that tidal heating from hyperons is dominant only for very massive neutron stars having masses 1.8 to 2.0 $M_{\odot }$, a successful detection of this phase shift during the inspiral of binary systems with relatively low masses of 1.4 to $1.6M_{\odot }$ could be a smoking gun signature for the existence of strange quark stars.

We explore the dynamics and gravitational-wave emission from black hole pairs on unbound orbits undergoing close hyperbolic encounters (CHEs) in dense astrophysical environments. While general relativity predicts gravitational bremsstrahlung radiation occurring at periastron, the contribution of the scalar gravitational-wave mode in fully general $f(R)$ gravity remains largely unexplored. We characterize the $f(R)$ scalar mode gravitational radiation for both nonprecessing and precessing hyperbolic orbits, identifying potential detection signatures for advanced gravitational-wave observatories. By systematically varying orbital precession and eccentricity, we examine their influence on the emitted gravitational waves. We derive potentially detectable time delay and scalar-to-tensor amplitude ratio estimates for representative astrophysical environments and determine optimal orbital configurations for the detection of $f(R)$ scalar gravitational waves from hyperbolic encounters. Our results provide the theoretical framework for scalar mode signals and observables, establishing CHEs as a promising probe of $f(R)$ gravity with future detectors.

Black holes gradually settle into their static configuration by emitting gravitational waves, whose amplitudes diminish over time according to a power-law decay at fixed spatial locations. We show that the nonlinear tails in the presence of a quadratic source, which have been recently found to potentially dominate over the linear ones, can be simply derived from the ${\mathrm{AdS}}_2\times {\mathrm{S}}^2$ spacetime perspective with their amplitudes being related to the Aretakis constants.

Under the assumptions of general relativity (GR), gravitational waves (GWs) propagate at the speed of light and their mediation can be represented as a particle through a massless graviton. We investigate the impact and observability of the presence of a massive graviton, how such a modification to GR would also modify the propagation of observed GWs from astrophysical sources, and how this effect can be used as an independent measurement of cosmological parameters. We demonstrate that a massive graviton allows the extraction of redshift information from the GWs signal, and propose a method to constrain cosmology, focusing on the Hubble parameter $H_0$ and matter energy ${\mathrm{\Omega }}_m$, with only GWs observations. We simulate the impact of a massive graviton on compact binary coalescence observations in a near-future Laser Interferometer Gravitational Wave Observatory-Virgo-Kamioka Gravitational Wave Detector interferometer network through a modification to the gravitational wave phase in the post-Newtonian framework. Our analysis finds that if we assume the presence of a graviton with a Compton wavelength of ${\lambda }_G\approx 5\times {10}^{16}\mathrm{m}$, corresponding to a mass $m_G\le 2.3\times {10}^{-23}\mathrm{eV}/{\mathrm{c}}^2$, we can utilize a simulated population of 60 binary black hole observations to constrain $H_0$ to a similar precision as current gravitational wave constraints without electromagnetic counterparts (at 90% credible intervals): $H_0=58_{-19}^{+34}\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$ and ${\mathrm{\Omega }}_m=0.29_{-0.08}^{+0.10}$. More sensitive observatories will be necessary to probe lower values in the graviton mass range and fully exploit this method.

Though an anti–de Sitter (AdS) vacuum, corresponding to a negative cosmological constant (NCC), can be not responsible for the acceleration of the current Universe, it might coexist with one evolving positive dark energy component at low redshift, as well as with early dark energy around the recombination to solve the Hubble tension. In this paper, we investigate the scenario with one AdS vacuum around the recombination and one at low redshift, and from both current observational and theoretical perspectives preliminarily explore the possibility that the Universe experienced a landscape with multiple AdS vacua since matter-radiation equality.

Resistive magnetohydrodynamics is thought to play a key role in transient high-energy astrophysical phenomena such as flares from black hole and neutron star magnetospheres. When performing numerical simulations of resistive magnetohydrodynamics, one is faced with the issue that Ampère’s law becomes stiff in the high conductivity limit which poses challenges to the numerical evolution. We show that using a description of resistive magnetohydrodynamics based on higher-form symmetry, one can perform simulations with a generalized dual Faraday tensor without having to use Ampère’s law, thereby avoiding the stiffness problem. We also explain the relation of this dual model to a traditional description of resistive magnetohydrodynamics and how causality is guaranteed by introducing second order corrections.

The slope of the neutron star mass-radius curve, $dM/dR$, is studied to understand the information it may carry about the composition of neutron stars, particularly with regard to the presence of non-nucleonic degrees of freedom. This study uses two large sets of relativistic mean-field equations of state with either nucleonic or nucleonic and hyperonic degrees of freedom, and imposes constraints obtained from GW170817 and the pulsars PSR $\mathrm{J}0030+0451$ and PSR $\mathrm{J}0740+6620$. It is shown that: (i) some mass-radius curves are characterized by a negative slope from one solar mass up to the maximum mass; (ii) other equations of state (EoSs) have a positive slope for a given range of masses below the maximum star mass. Within the set of models considered, the first set includes only a very small number of hyperonic EoSs: fewer than 0.5% of the total number of hyperonic stars and approximately one third of the nucleonic EoS. We have also analyzed the sign of the slope for neutron star masses of 1.2, 1.4 and $1.8M_{\odot }$. Only approximately 1% of hyperonic EoSs predict a negative slope for $1.4M_{\odot }$ stars, whereas over 90% of nucleonic stars have a negative slope at this mass. Finally, almost all stars have a negative slope at $1.8M_{\odot }$. A positive slope at $1.4M_{\odot }$ may indicate the presence of non-nucleonic degrees of freedom within neutron stars. The nuclear matter property that distinguishes the different scenarios most clearly is the curvature of the symmetry energy. Nucleonic EoSs with a positive slope $dM/dR$ predict the highest values, which can exceed 100 MeV.

The Laser Interferometer Space Antenna (LISA) aims to detect gravitational waves by interferometrically measuring the separation between free falling test masses (TMs) with $\mathrm{pm}/\sqrt{\mathrm{Hz}}$ sensitivity down to mHz frequencies. Achieving this sensitivity requires the suppression of spurious path length variations induced by unavoidable tilts of the TMs and spacecraft, a phenomenon known as tilt-to-length coupling. LISA employs differential wave front sensing (DWS) to measure angular misalignments between the interfering beams’ wave fronts. To first-order approximation, the DWS signal is linearly dependent on the tilt angle for small angular displacements (on the order of microradians). The linear coupling coefficient is well-documented for the idealized case of a photodiode (PD) much larger than the beam spot radius. However, LISA’s setup violates this assumption, and the anticipated tilt range exceeds the linear regime. Accurately characterizing the DWS signal thus requires a more comprehensive approach. This paper presents a novel analytical framework for calculating the first two Maclaurin coefficients of the DWS signal for two fundamental-mode Gaussian beams with a small wave front curvature mismatch, incident on PDs of arbitrary size. The validity of this approach is verified by comparison with numerical simulations and experimental calibrations conducted on an ultrastable testbed representative of LISA. Moreover, we utilize this framework to determine the phase sensitivity required to meet LISA’s stringent measurement requirements. The results of this paper will facilitate the calculation of the DWS gain of an interferometric topology and give a reference target to the experiments aiming to demonstrate LISA’s performance requirement.

We study fermion zero-mode wave functions with various chiralities in the magnetized $T^{2g}$, ($g=2,3$), torus. First, we consider the wave functions satisfying the Dirac equation and the boundary conditions on the magnetized torus. Second, we introduce the $SO(3)$ (or parity) transformations and derive the wave functions under the modular transformation. Additionally, we calculate the Yukawa couplings taking chirality into account. Lastly, we briefly review how to construct the $T^4/{\mathbb{Z}}_N$, ($N=2,3,4,6$), and $T^6/{\mathbb{Z}}_{12}$ twisted orbifold. Also, we explicitly analyze the number of the wave functions in ${\mathbb{Z}}_N$ sectors.

A multicomponent weakly-interacting dark matter scenario is analyzed, where the candidate dark matter states arise from the $SU(2{)}_D\to Z_3^D\times Z_2^{\mathrm{acc}}$ symmetry breaking triggered by a vacuum expectation value-developing scalar in the $J=3/2$ representation. While the discrete symmetries guarantee at least two stable states, a closer look at the mass orderings of the contrived dark sector reveals the existence of a third dark matter candidate, whose stability effectively results from the tight phase space in the dark boson sector. Regions of masses and couplings where the three dark states furnish a comparable contribution to the observed relic abundance are determined numerically.

This paper investigates an inverse seesaw model of neutrino masses based on nonholomorphic modular $A_4$ symmetry, extending the framework of modular-invariant flavor models beyond the conventional holomorphic paradigm. After the general theoretical framework is established, three concrete model realizations distinguished by their $A_4$ representation assignments and modular weight configurations for the matter fields are analyzed. Focusing on these three specific realizations, a comprehensive analysis of neutrino phenomenology is performed. By constraining the modulus parameter $\tau$ to the fundamental domain and systematically scanning the parameter space, regions compatible with current neutrino oscillation data are identified. The numerical results provide predictions for currently unmeasured quantities, including the absolute neutrino mass scale, Dirac $CP$-violating phase, and Majorana phases. These predictions establish specific, testable signatures for upcoming neutrino experiments, particularly in neutrinoless double beta decay and precision oscillation measurements. The framework offers a well-defined target for future experimental verification or exclusion, while demonstrating the phenomenological viability of nonholomorphic modular symmetry approaches to flavor structure.

We present the first comprehensive sensitivity study of the Search for Hidden Particles (SHiP) experiment to sterile neutrino oscillations using all three types of neutrinos, employing a Feldman-Cousins method with a parametric bootstrap to account for systematic uncertainties. In contrast to earlier studies that focused only on ${\nu }_{\tau }$ disappearance, we include both appearance and disappearance channels across all active flavors. We also investigate the dual-baseline configuration, which complements the existing near scattering and neutrino detector (SND) at 27 m with an additional far SND at 120 m. The near SND only configuration can probe mixing parameters of $|U_{\alpha 4}{|}^2\gtrsim 0.1$ near $\mathrm{\Delta }{m}_{41}^2\sim {10}^3{\mathrm{eV}}^2$, with a reduction of normalized systematic uncertainties from 20% to 10% improving sensitivity by roughly a factor of two. Moreover, the inclusion of far SND significantly enhances the sensitivity by a factor of 2 to 10 depending on the flavor and the systematic uncertainty. If two active flavors are mixed with a sterile flavor, a cancelation between neutrino appearance and disappearance generates kinks in the sensitivity curves, while those kinks disappear with far SND.

We present state-of-the-art hadron-level predictions for the deep-inelastic scattering process at next-to-leading-order precision for several multiplicities, consistently merged in one sample. For the first time at this level of accuracy, we consider both neutral and charged current deep-inelastic scattering at the Electron-Ion Collider and present the first application of consistent next-to-leading-order merging to charged current deep-inelastic scattering in general. We critically examine inclusive predictions using multileg merging techniques, contrasting perturbative and nonperturbative uncertainties. Further, we study typical kinematic deep-inelastic scattering observables as well as jet measurements and 1-jettiness with realistic cuts implied by expected and past detector resolution. On the perturbative side, we see large corrections toward small virtualities and Bjorken-$x$, which can be captured by higher-multiplicity matrix elements and the merging procedure. Nonperturbative effects, while negligible in most jet observables, can reach similar size as the perturbative uncertainties around the peak of the 1-jettiness distributions especially at low values of $Q^2$.

Within the diquark-antidiquark framework, this study investigates the masses of ground-state tetraquarks composed of heavy charm ($c$) and bottom ($b$) quarks and antiquarks, using the Bethe-Salpeter formalism. We establish the Bethe-Salpeter equations for the fully heavy $bc\overline{b}\overline{c}$ tetraquarks to the leading order in $1/m_Q$ expansion. These equations are subsequently solved numerically under the covariant instantaneous approximation with kernels containing scalar confinement and one-gluon exchange terms. Our results show that the spectra of all possible $S$-wave tetraquark states are above the corresponding two lowest meson decay thresholds via the quark rearrangement. This implies that the ground $bc\overline{b}\overline{c}$ tetraquark states should be broad.

We perform a global analysis of lattice and experimental data on negative-strangeness meson-baryon scattering using a large set of variations of the theoretical framework based on the chiral unitary approach. For the former, the Lüscher formalism is utilized taking into account all pertinent coupled-channel effects. Through this, systematic uncertainties related to data scarcity, potential ambiguities, and possible framework dependence are quantified for the first time. The implementation of information criteria and other statistical tools is discussed. As a final result we provide pole positions for isoscalar resonances at the physical and lattice points, including statistical and systematic uncertainties. Predictions for the isovector states are also provided, showing large uncertainties.