In this work we study the thermodynamics of a ($2+1$)-dimensional static black hole under a nonlinear electric field. In addition to standard approaches, we investigate black hole thermodynamic geometry. We compute Weinhold and Ruppeiner metrics and compare the thermodynamic geometries with the standard description for black hole thermodynamics. We further consider the cosmological constant as an additional extensive thermodynamic variable. For thermodynamic equilibrium in three-dimensional space, we compute heat engine efficiency and show that it may be constructed with this black hole.

A condition is defined which determines if a supertranslation is induced in the course of a general evolution from one isolated horizon phase to another via a dynamical horizon. This condition fixes preferred slices on an isolated horizon and is preserved along an isolated horizon. If it is not preserved, in the course of a general evolution, then a supertranslation will be said to have been induced. A simple example of spherically symmetric dynamical horizons is studied to illustrate the conditions for inducing supertranslations.

Density perturbations related to structure formations are expected to be different in dissipative and nondissipative universes, even if the background evolution of the two universes is the same. To clarify the difference between the two universes, first-order density perturbations are studied, using two types of holographic cosmological models. The first type is a “$\mathrm{\Lambda }(t)$ model” similar to a time-varying $\mathrm{\Lambda }(t)$ cosmology for the nondissipative universe. The second type is a “BV model” similar to a bulk viscous cosmology for the dissipative universe. To systematically examine the two different universes, a power-law term proportional to $H^{\alpha }$ is applied to the $\mathrm{\Lambda }(t)$ and BV (bulk-viscous-cosmology-like) models, assuming a flat Friedmann-Robertson-Walker model for the late universe. Here, $H$ is the Hubble parameter and $\alpha$ is a free parameter whose value is a real number. The $\mathrm{\Lambda }(t)\text{−}{H}^{\alpha }$ and $\mathrm{BV}\text{−}{H}^{\alpha }$ models are used to examine first-order density perturbations for matter, in which the background evolution of the two models is equivalent. In addition, thermodynamic constraints on the two models are discussed, with a focus on the maximization of entropy on the horizon of the universe, extending previous analyses [Phys. Rev. D 100, 123545 (2019); Phys. Rev. D102, 063512 (2020)]. Consequently, the $\mathrm{\Lambda }(t)\text{−}{H}^{\alpha }$ model for small $|\alpha |$ values is found to be consistent with observations and satisfies the thermodynamic constraints, compared with the $\mathrm{BV}\text{−}{H}^{\alpha }$ model. The results show that the nondissipative universe described by the $\mathrm{\Lambda }(t)\text{−}{H}^{\alpha }$ model similar to lambda cold dark matter models is likely favored.

The nature of nucleon resonances is still being debated, while much experimental data are accumulated. In this work, we focus on the negative parity resonance $N^{*}(1895)$ which is located in the scattering region of various meson-baryon coupled channels, and such dynamics can be crucial in understanding its properties. To test the relevance of such hadron dynamics, we investigate the decay properties of $N^{*}(1895)$ in detail. We examine how a two pole nature of $N^{*}(1895)$ is compatible with its observed decay properties. Moreover, we find that the resonance decays into final states involving $\mathrm{\Lambda }(1405)$ and $\mathrm{\Sigma }(1400)$, where the latter is not yet observed experimentally. Such decay processes can be useful to study the properties of the aforementioned hyperon resonances.

Supersymmetric (SUSY) extension of the Standard Model (SM) is a primary candidate for new physics beyond the SM. If SUSY breaking scale is very low, for example, the multi-TeV range, and the SUSY breaking sector, except for the Goldstino (gravitino), is decoupled from the low energy spectrum, the hidden sector effect in the minimal SUSY SM (MSSM) is well described by employing the Goldstino chiral superfield ($X$) with the nilpotent condition of $X^2=0$. Although this so-called “nonlinear MSSM” (NL-MSSM) provides a variety of interesting phenomenologies, there is a cosmological problem that the lightest superpartner gravitino is too light to be the major component of the dark matter (DM) in our Universe. To solve this problem, we propose a minimal extension of the NL-MSSM by introducing a parity-odd SM singlet chiral superfield ($\mathrm{\Phi }$). We show that the interaction of the scalar component in $\mathrm{\Phi }$ with the MSSM Higgs doublets is induced after eliminating $F$ component of the Goldstino superfield, and the lightest real scalar in $\mathrm{\Phi }$ plays the role of the Higgs-portal DM. With a suitable choice of the model parameters, a successful Higgs-portal DM scenario can be realized. In addition, if SUSY breaking scale lies in the multi-TeV range, the SM-like Higgs boson mass of 125 GeV can be achieved by the tree-level Higgs potential through the low-scale SUSY breaking effect.

We show possible transverse-momentum-dependent parton distribution functions (TMDs) for spin-1 hadrons including twist-3 and twist-4 functions in addition to the leading twist-2 ones by investigating all the possible decomposition of a quark correlation function in the Lorentz-invariant way. The Hermiticity and parity invariance are imposed in the decomposition; however, the time-reversal invariance is not used due to an active role of gauge links in the TMDs. Therefore, there exist time-reversal-odd functions in addition to the time-reversal even ones in the TMDs. We list all the functions up to twist-4 level because there were missing terms associated with the light cone vector $n$ in previous works on the twist-2 part and there was no correlation-function study in the twist-3 and twist-4 parts for spin-1 hadrons. We show that 40 TMDs exist in the tensor-polarized spin-1 hadron in twists 2–4. Some expressions of twist-2 structure functions are modified from previous derivations due to the new terms with $n$, and we find 30 new structure functions in twists 3 and 4 in this work. Since time-reversal-odd terms of the collinear correlation function should vanish after integrals over the partonic transverse momentum, we obtain new sum rules for the time-reversal-odd structure functions, $\int d^2{k}_T{g}_{LT}=\int d^2{k}_T{h}_{LL}=\int d^2{k}_T{h}_{3LL}=0$. In addition, we indicate that new transverse-momentum-dependent fragmentation functions exist in tensor-polarized spin-1 hadrons. The TMDs are rare observables to find explicit color degrees of freedom in terms of color flow, which cannot be usually measured because the color is confined in hadrons. Furthermore, the studies of TMDs enable us not only to find three-dimensional structure of hadrons, namely, hadron tomography including transverse structure, but also to provide unique opportunities for creating interesting interdisciplinary physics fields such as gluon condensates, color Aharonov-Bohm effect, and color entanglement. The tensor structure functions may not be easily measured in experiments. However, high-intensity facility such as the Thomas Jefferson National Accelerator Facility, the Fermilab Main Injector, and future accelerators like electron-ion collider may probe such observables. In addition, since the Nuclotron-based Ion Collider fAcility focuses on spin-1 deuteron structure functions, there is a possibility to study the details of polarized structure functions of the deuteron at this facility.

The covariant parton model is generalized to describe quark correlators in a systematic way. Previous results are reproduced for the T-even leading-twist transverse momentum dependent parton distribution functions (TMDs), and for the first time all T-even twist-3 TMDs are evaluated in this model. We apply the approach to evaluate the fully unintegrated quark correlator which allows us to understand the model-specific relations between different TMDs. We verify the consistency of the approach, present numerical results and compare to available TMD parametrizations.

We present the full charge and energy diffusion constants for the Einstein-Maxwell dilaton (EMD) action for Lifshitz spacetime characterized by a dynamical critical exponent $z$. Therein we compute the fully renormalized static thermodynamic potential explicitly, which confirms the forms of all thermodynamic quantities including the Bekenstein-Hawking entropy and Smarr-like relationship. All thermodynamics are based on a direct computation of the free energy. Our exact computation demonstrates a modification to the Lifshitz-Ward identity for the EMD theory. For transport, we target our analysis at finite chemical potential and include axion fields to generate momentum dissipation. While our exact results corroborate anticipated bounds, we are able to demonstrate that the diffusivities are governed by the engineering dimension of the diffusion coefficient, $[D]=2-z$. Consequently, a $\beta$ function defined as the derivative of the trace of the diffusion matrix with respect to the effective lattice spacing changes sign precisely at $z=2$. At $z=2$, the diffusion equation exhibits perfect scale invariance and the corresponding diffusion constant is the pure number $1/d_s$ for both the charge and energy sectors, where $d_s$ is the number of spatial dimensions. Further, we find that as $z\to \infty$, the charge diffusion constant vanishes, indicating charge localization. Deviation from universal decoupled transport obtains when either the chemical potential or momentum dissipation are large relative to temperature, an echo of strong thermoelectric interactions.

The detection of a stochastic background of low-frequency gravitational waves by pulsar-timing and astrometric surveys will enable tests of gravitational theories beyond general relativity. These theories generally permit gravitational waves with non-Einsteinian polarization modes, which may propagate slower than the speed of light. We use the total-angular-momentum wave formalism to derive the angular correlation patterns of observables relevant for pulsar timing arrays and astrometry that arise from a background of subluminal gravitational waves with scalar, vector, or tensor polarizations. We find that the pulsar timing observables for the scalar longitudinal mode, which diverge with source distance in the luminal limit, are finite in the subluminal case. Furthermore, we apply our results to $f(R)$ gravity, which contains a massive scalar degree of freedom in addition to the standard transverse-traceless modes. The scalar mode in this $f(R)$ theory is a linear combination of the scalar-longitudinal and scalar-transverse modes, exciting only the monopole and dipole for pulsar timing arrays and only the dipole for astrometric surveys.

The discrepancy between early-Universe inferences and direct measurements of the Hubble constant, known as the Hubble tension, recently became a pressing subject in high precision cosmology. As a result, a large variety of theoretical models have been proposed to relieve this tension. In this work we analyze a conformally coupled modified gravity (CCMG) model of an evolving gravitational constant due to the coupling of a scalar field to the Ricci scalar, which becomes active around matter-radiation equality, as required for solutions to the Hubble tension based on increasing the sound horizon at recombination. The model is theoretically advantageous as it has only one free parameter in addition to the baseline $\mathrm{\Lambda }$ cold dark matter ones. Inspired by similar recent analyses of so-called early dark energy models, we constrain the CCMG model using a combination of early- and late-Universe cosmological datasets. In addition to the Planck 2018 cosmic microwave background (CMB) anisotropies and weak lensing measurements, baryon acoustic oscillations, and the Supernova H0 for the Equation of State datasets, we also use large-scale structure (LSS) datasets such as the Dark Energy Survey Year 1 and the full-shape power spectrum likelihood from the Baryon Oscillation Spectroscopic Survey, including its recent analysis using effective field theory, to check the effect of the CCMG model on the (milder) $S_8$ tension between the CMB and LSS. We find that the CCMG model can slightly relax the Hubble tension, with $H_0=69.6\pm 1.6\mathrm{km}/\mathrm{s}/\mathrm{Mpc}$ at 95% confidence level, while barely affecting the $S_8$ tension. However, current data does not exhibit a strong preference for CCMG over the standard cosmological model. Lastly, we show that the planned CMB-S4 experiment will have the sensitivity required to distinguish between the CCMG model and the more general class of models involving an evolving gravitational constant.

Our first goal in this work is to study general and model-independent properties of cyclic cosmologies. The large number of studies of bouncing cosmologies and different cyclic scenarios published recently call for a proper understanding of the universal properties of cyclic models. We thus first review and further elaborate the common physical and geometrical properties of various classes of cyclic models and then discuss how the cyclic Universe can be treated as a dynamic system. We then discuss how two theorems from dynamic systems analysis can be used to ensure the existence of cyclic cosmological solutions under certain conditions on the field equations. After this we proceed toward our second goal which is the application of the obtained results to different frameworks of modified gravity theories: $f(R)$ gravity, dynamic dark energy, and $f(T)$ gravity. We discuss the general requirements for the existence of cyclic solutions in these theories and also obtain various examples of cyclic cosmologies, while discussing their basic properties.

We scrutinize the XENON1T electron recoil excess in the scalar-singlet-extended dark matter effective field theory. We confront it with various astrophysical and laboratory constraints both in a general setup and in the more specific, recently proposed, variant with leptophilic $Z_2$-odd mediators. The latter also provide mass to the light leptons via suppressed $Z_2$ breaking, a structure that is well fitting with the nature of the observed excess and the discrete symmetry leads to nonstandard dark-matter interactions. We find that the excess can be explained by neutrino–electron interactions, linked with the neutrino and electron masses, while dark-matter–electron scattering does not lead to statistically significant improvement. We analyze the parameter space preferred by the anomaly and find severe constraints that can only be avoided in certain corners of parameter space. Potentially problematic bounds on electron couplings from big-bang nucleosynthesis can be circumvented via a late phase transition in the new scalar sector.

General relativistic, axisymmetric flow of low angular momentum accretion around a Kerr black hole can assume certain geometric configurations where the flow is maintained in hydrostatic equilibrium along the vertical direction (the direction orthogonal to the equatorial plane of the flow). The flow thickness for such accretion models becomes a function of the local radial distance measured from the black hole horizon. There are three types of functions defined in the literature which resemble the thickness of the flow for such a configuration. We formulate the equations governing the steady state astrophysical accretion characterized by both the polytropic as well as the isothermal equation of state in classical thermodynamics. We solve the equations within the framework of such geometric configuration for three different thickness functions to obtain the multitransonic, shocked, stationary integral accretion solutions. Such solutions enable us to study how flow thickness influences the dependence of the properties of postshock flows on black hole spin angular momentum, i.e., the Kerr parameter. For temperature-preserving standing shocks, we find that the postshock part of the disc can become luminous, and a considerable amount of gravitational energy carried by the accreting fluid gets liberated at the shock. We find which kind of thickness function produces the maximum liberated energy, making the disc most luminous.

First proposed in 2013 by Yagi and Yunes, the quasiuniversal I-Love-Q relations consist of a set of relations between the moment of inertia, the spin-induced quadrupole moment and the electric quadrupolar tidal deformability of neutron stars which are independent of the equation of state within an accuracy of $\sim 1\%$. In this work, we show that these relations hold for different Skyrme-based nuclear matter equation of state and also for the starlike solutions of different Einstein-BPS-Skyrme models - where BPS stands for Bogomolnyi-Prasad-Sommerfield, some of which do not even present a barotropic equation of state. Further, other quasiuniversal relations are analyzed, and, together with recent gravitational wave observations, we use them to select the generalized Skyrme model that better reproduces observations. Our results reaffirm both the universality of the I-Love-Q relations and the suitability of generalized Skyrme models to describe nuclear matter inside neutron stars.

Thermal distortion of test masses, as well as thermal drift of their vibrational mode frequencies, present a major challenge for operation of the Advanced LIGO and Advanced VIRGO interferometers, reducing optical efficiency, which limits sensitivity and potentially causing instabilities which reduce duty-cycle. In this paper, we demonstrate that test-mass vibrational mode frequency data can be used to overcome some of these difficulties. First, we derive a general expression for the change in a mode frequency as a function of temperature distribution inside the test mass. Then we show how the mode frequency dependence on temperature distribution can be used to identify the wave function of observed vibrational modes. We then show how monitoring the frequencies of multiple vibrational modes allows the temperature distribution inside the test mass to be strongly constrained. Finally, we demonstrate using simulations, the potential to improve the thermal model of the test mass, providing independent and improved estimates of important parameters such as the coating absorption coefficient and the location of point absorbers.

The CMS phase II track trigger may allow for a displaced dimuon vertex trigger with qualitatively lower $p_T$ thresholds than existing dimuon triggers. With this technique, we show that the CMS reach for exotic $B$-meson decays involving a displaced dimuon resonance, such as a light, Higgs-mixed scalar, can be competitive with that of LHCb and Belle II.

In this study we consider an extension of the Standard Model with a complex hypercharge zero triplet scalar. In this scenario one of the charged Higgs bosons remains purely triplet and does not couple to the fermions, making it elusive at colliders. Also the physical pseudoscalar is a pure triplet and this purity makes it a suitable dark matter candidate without the need of discrete symmetries, unlike other extensions. The bounds from relic density and direct dark matter search experiments select its mass to be $\sim 1.35–1.60\mathrm{TeV}$. The pure triplet charged Higgs gives rise to displaced signatures and their sensitivity at LHC and MATHUSLA have been studied. The prospects at present and future hadron/muon colliders of such exotic scalars are pointed out by calculating their productions cross section and dominant decay modes. We present also the expected reach for the triplet states at a multi-TeV muon collider.

A cosmologically stable neutral component from a nearly pure $SU(2)$ doublet, with a mass $\sim 1.1\mathrm{TeV}$, is one appealing candidate for dark matter (DM) consistent with all direct dark matter searches. We explore this possibility in the context of the minimal supersymmetric extension of the Standard Model, with the Higgsino playing the role of DM, in theories where supersymmetry breaking is transmitted by gravitational interactions at the unification scale $M\simeq 2\times {10}^{16}\mathrm{GeV}$. We focus on the search for “light” supersymmetric spectra, which could be within reach of present and/or future colliders, in models with universal and nonuniversal Higgs and gaugino Majorana masses. The lightest supersymmetric particles of the spectrum are, by construction, two neutralinos and one chargino, almost degenerate, with a mass $\sim 1.1\mathrm{TeV}$, and a mass splitting of a few GeV. Depending on the particular scenario the gluino can be at its experimental lower mass bound $\sim 2.2\mathrm{TeV}$; in the squark sector, the lightest top squark can be as light as $\sim 1.6\mathrm{TeV}$, and the lightest slepton, the right-handed stau, can have a mass as light as 1.2 TeV. The lightest neutralino can be found in the next generation of direct dark matter experimental searches. In the most favorable situation, the gluino, with some specific decay channels, could be found during the next run of the LHC, and the lightest top squark during the high-luminosity LHC run.

Two field-sparsening methods, namely the sparse-grid method and the random field selection method, are used in this paper for the construction of the 2-point and 3-point correlation functions in lattice QCD. We argue that, due to the high correlation among the lattice correlators at different field points associated with source, current, and sink locations, one can save a lot of computational time by performing the summation over a subset of the lattice sites. Furthermore, with this strategy, one only needs to store a small fraction of the full quark propagators. It is found that the number of field points can be reduced by a factor of $\sim 100$ for the point-source operator and a factor of $\sim 1000$ for the Gaussian-smeared operator, while the uncertainties of the correlators only increase by $\sim 15\%$. Therefore, with a modest cost of the computational resources, one can approach the precision of the all-to-all correlators using the field-sparsening methods.