Renormalization group flows of the $SU(N_f)\times SU(N_f)$ symmetric Ginzburg-Landau potential are calculated for a general number of flavors, $N_f$. Our approach does not rely on the $\epsilon$ expansion, but uses the functional renormalization group, formulated directly in $d=3$ spatial dimensions, with the inclusion of all possible (perturbatively) relevant and marginal operators, whose number is considerably larger than those in $d=4$. We find new, potentially infrared stable fixed points spanned throughout the entire $N_f$ range. By conjecturing that the thermal chiral transition is governed by these “flavor continuous” fixed points, stability analyses show that for $N_f\ge 5$ the chiral transition is of second order, while for $N_f=2$, 3, 4, it is of first order. We argue that the $U_{\mathrm{A}}(1)$ anomaly controls the strength of the first-order chiral transition for $N_f=2$, 3, 4, and makes it almost indistinguishable from a second-order one, if it is sufficiently weak at the critical point. This could open up a new strategy to investigate the strength of the $U_{\mathrm{A}}(1)$ symmetry breaking around the critical temperature.

We present the differential predictions for the rapidity distribution of pseudoscalar Higgs boson through gluon fusion at the LHC. These results are obtained taking into account the soft-virtual (SV) as well as the next-to-soft virtual (NSV) resummation effects to next-to-next-to-leading-logarithmic ($\overline{\mathrm{NNLL}}$) accuracy and matching them to the approximate fixed order next-to-next-to-leading-order (${\mathrm{NNLO}}_{\mathrm{A}}$) computation. We perform the resummation in two-dimensional Mellin space by limiting ourselves to the contributions only from gluon-gluon ($gg$) initiated channels. The ${\mathrm{NNLO}}_{\mathrm{A}}$ rapidity distribution of pseudoscalar Higgs is obtained by applying a ratio method on the NNLO rapidity distribution of the scalar Higgs boson. We also present the first analytical results of ${\mathrm{N}}^3\mathrm{LO}$ rapidity distribution of pseudoscalar Higgs at $\mathrm{SV}+\mathrm{NSV}$ accuracy. The phenomenological impacts of ${\mathrm{NNLO}}_{\mathrm{A}}+\overline{\mathrm{NNLL}}$ predictions for 13 TeV LHC are studied. We observe that for $m_A=125(700)\mathrm{GeV}$ the $\mathrm{SV}+\mathrm{NSV}$ resummation at the $\overline{\mathrm{NNLL}}$ level brings about 14.76% (11.48%) corrections to the ${\mathrm{NNLO}}_{\mathrm{A}}$ results at the central scale value of ${\mu }_R={\mu }_F=m_A$. Further, we find that the sensitivity to the renormalization scale gets improved substantially by the inclusion of NSV resummed predictions at $\overline{\mathrm{NNLL}}$ accuracy.

We compute the one-loop contribution to the $\overline{\theta }$ parameter of an faxionlike particle (ALP) with $CP$-odd derivative couplings. Its contribution to the neutron electric dipole moment is shown to be orders of magnitude larger than that stemming from the one-loop ALP contributions to the up- and down-quark electric and chromoelectric dipole moments. This strongly improves existing bounds on ALP-fermion $CP$-odd interactions and also sets limits on previously unconstrained couplings. The case of a general singlet scalar is analyzed as well. In addition, we explore how the bounds are modified in the presence of a Peccei-Quinn symmetry.

We compute the vacuum energy density as a function of the quark condensate in the interacting instanton liquid model (IILM) and examine the pattern of dynamical chiral symmetry breaking from its behavior around the origin. This evaluation is performed by using simulation results of the IILM. We find that chiral symmetry is broken in the $\mathrm{U}(1{)}_A$ anomaly assisted way in the IILM with three-flavor dynamical quarks. We call such a symmetry breaking the anomaly-driven breaking, which is one of the scenarios of chiral symmetry breaking proposed in the context of the chiral effective theories. We also find that the instanton-quark interaction included in the IILM plays a crucial role for the anomaly-driven breaking by comparing the full and the quenched IILM calculations.

In this work, we investigate possible bound states of the ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ system in the Bethe-Salpeter formalism in the ladder and instantaneous approximations. By numerically solving the Bethe-Salpeter equation, we confirm the existence of ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ bound states with quantum numbers $J^{PC}=0^{-+}$ and $J^{PC}=1^{--}$. We further investigate the partial decay widths of the ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ bound states into $N\overline{N}$, $D\overline{D}$, $D{\overline{D}}^{*}$, $D^{*}{\overline{D}}^{*}$, $\pi \overline{\pi }$, and $K\overline{K}$. Our results indicate that the decay width of the ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ bound state with $J^{PC}=1^{--}$ is much larger than that with $J^{PC}=0^{-+}$, and among their decay channels, the $D{\overline{D}}^{*}$ final state is the main decay mode. We suggest experiments to search for the ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$ bound states in the $D{\overline{D}}^{*}$ final state.

We have investigated the process $J/\psi \to {\overline{K}}^0{K}^{+}{\rho }^{-}$ by taking into account the $S$-wave $K^{*}{\overline{K}}^{*}$, $\rho \omega$, and $\rho \varphi$ final-state interactions, where the scalar meson $a_0(1710)$ is generated. In addition, we also take into account the contributions from the scalar $a_0(980)(\to {\overline{K}}^0{K}^{+})$ and the intermediate resonances $K_1(1270{)}^{-}(\to {\overline{K}}^0{\rho }^{-})$ and $K_1(1270{)}^0(\to K^{+}{\rho }^{-})$. Our results show that, in the ${\overline{K}}^0{K}^{+}$ invariant mass distribution, a clear peak structure around 1.8 GeV appears, which could be associated with the scalar $a_0(1710)$, however, no significant structure of the $a_0(980)$ is observed. On the other hand, one can find clear peaks of the $K_1(1270)$ in the ${\overline{K}}^0{\rho }^{-}$ and $K^{+}{\rho }^{-}$ invariant mass distributions. The future precise measurement of this process by the BESIII and Belle II Collaborations and the planned Super Tau-Charm Facility in the future could shed light on the nature of $a_0(1710)$.

Computing leading higher curvature contributions to thermodynamic quantities of AdS black hole is drastically simplified once the higher curvature terms are expressed in terms of powers of Weyl tensor by applying proper field redefinitions, avoiding the usual complications caused by higher derivative Gibbons-Hawking-York term or surface counterterms. We establish the method by computing the Euclidean action of general rotating anti–de Sitter (AdS) black holes in five-dimensional quadratic curvature theories with or without supersymmetry and verifying the results numerically. Our result is the state of the art for charged rotating AdS black holes in five-dimensional minimal gauged supergravity including corrections from all three supersymmetric curvature squared terms. Our approach facilitates precision tests in the AdS/CFT correspondence and should be applicable in diverse dimensions.

This work challenges the conventional notion that in a spacetime dimension higher than one, a supersymmetric Lagrangian invariably consists of purely bosonic terms, purely fermionic terms, as well as boson-fermion mixing terms. By recasting a relativistic Lagrangian in terms of its nonrelativistic and ultrarelativistic sectors, we reveal that an ultrarelativistic (Carrollian) supersymmetric Lagrangian exhibits an exotic feature; that is, it can exist without a purely bosonic contribution. Based on this result, we demonstrate a link between higher-dimensional Carrollian and ($0+1$)-dimensional quantum mechanical models, yielding higher-order extensions of supersymmetric Sachdev-Ye-Kitaev (SYK) models in which purely bosonic higher-order terms are absent. Given that supersymmetry plays an essential role in improving the quantum behavior and solubility, our findings may lead to interesting applications in non-AdS holography.

We establish a cosmological-model-independent method to extract the apparent magnitude and its derivative at different redshifts from the $\mathrm{Pantheon}+$ type Ia supernova sample and find that the obtained values deviate clearly from the prediction of the $\mathrm{\Lambda }\mathrm{CDM}$ model at the lowest redshift. This deviation can be explained as a result of a transition of the absolute magnitude $M$ in the low-redshift region. The observations seem to favor this transition, since the minimum values of ${\chi }^2$ for two Ansätze of a varying $M$ are less than that of a constant $M$. The Hubble-constant tension is alleviated from larger than $5\sigma$ to be about $1\sigma –2\sigma$ for a varying $M$, and the growth tension can be resolved after attributing the variation of $M$ to a modification of the effective Newton’s constant.

We investigate the phenomenon of electron-positron pair production from vacuum in the presence of a strong electric field of circular polarization. By means of a nonperturbative approach based on the quantum kinetic equations (QKEs), we numerically calculate helicity-resolved momentum distributions of the particles produced and analyze the corresponding helicity asymmetry. It is demonstrated that the external rotating field tends to generate left-handed and right-handed particles traveling in opposite directions. Generic symmetry properties of the momentum spectra are examined analytically by means of the QKEs and also confirmed and illustrated by direct numerical computations. The helicity signatures revealed in our study are expected to provide a firmer basis for possible experimental investigations of the fundamental phenomenon of vacuum pair production in strong fields.

Recent observations of high-energy neutrinos from active galactic nuclei (AGN), NGC 1068 and TXS $0506+056$, suggest that cosmic rays (CRs) are accelerated in the vicinity of the central supermassive black hole and high-energy protons and electrons can cool efficiently via interactions with ambient photons and gas. The dark matter density may be significantly enhanced near the black hole, and CRs could lose energies predominantly due to scatterings with the ambient dark matter particles. We propose CR cooling in AGN as a new probe of dark matter-proton and dark matter-electron scatterings. Under plausible astrophysical assumptions, our constraints on sub-GeV dark matter can be the strongest derived to date. Some of the parameter space favored by thermal light dark matter models might already be probed with current multimessenger observations of AGN.

We investigate the relaxation of holographic superfluids after quenches, when the end state is either tuned to be exactly at the critical point, or very close to it. By solving the bulk equations of motion numerically, we demonstrate that in the former case the system exhibits a power law falloff, as well as an emergent discrete scale invariance. The latter case is in the regime dominated by critical slowing down, and we show that there is an intermediate time range before the onset of late-time exponential falloff, where the system behaves similarly to the critical point with its power law falloff. We further postulate a phenomenological Gross-Pitaevskii-like equation (corresponding to model F of Hohenberg and Halperin) that is able to make quantitative predictions for the behavior of the holographic superfluid after near-critical quenches into the superfluid and normal phase. Intriguingly, all parameters of our phenomenological equation, which describes the nonlinear time evolution, may be fixed with information from the static equilibrium solutions and linear response theory.

We identify a categorical structure of the set of all conformal field theories (CFTs). In particular, we show that the set of all CFTs has a natural monoidal strict 2-category structure with the 1-morphisms being sequences of deformations and 2-morphisms determined by 0-form symmetries of the CFTs.

A communication protocol with nonzero quantum capacity is found when the two communicating parts are particle detector models in ($3+1$)-dimensional spacetime. In particular, as detectors, we consider two harmonic oscillators interacting with a scalar field, whose evolution is generalized for whatever background spacetime and whatever spacetime smearing of the detectors. We then specialize to Minkowski spacetime and an initial Minkowski vacuum, considering a rapid interaction between the field and the two detectors, studying the case where the receiver is static and the sender is moving. The possibility to have a quantum capacity greater than zero stems from a relative acceleration between the detectors. Indeed, no reliable quantum communication is possible when the two detectors are static or moving inertially with respect to each other, but a reliable quantum communication can be achieved between a uniformly accelerated sender and an inertial receiver.

We consider the renormalization group flow equation for the two-dimensional sigma models with the Kähler target space. The first-order formulation allows us to treat perturbations in these models as current-current deformations. We demonstrate, however, that the conventional first-order formalism misses certain anomalies in the measure, and should be amended. We reconcile beta functions obtained within the conformal perturbation theory for the current-current deformations with traditional “geometric” results obtained in the background field methods, in this way resolving the peculiarities pointed out in O. Gamayun et al. [Peculiarities of beta functions in sigma models, J. High Energy Phys. 10 (2023) 097]. The result is achieved by the supersymmetric completion of the first-order sigma model.

In the context of $f(R,T)$ gravity and other modified theories of gravity, the knowledge of the first order variation of the trace $T$ of the energy-momentum tensor with respect to the metric is essential for an accurate characterization of the gravitational field. In this paper, by considering a paradigmatic example of a perfect fluid whose dynamics is described by a pure k-essence matter Lagrangian in $f(R,T)=R+\mathcal{F}(T)$ gravity, we show that the first order variation of the trace of the energy-momentum tensor cannot in general be determined from the proper density, proper pressure, and 4-velocity of the fluid alone, and that the sound speed of the fluid can directly influence the dynamics of gravity. We also confirm that the second variation of the matter Lagrangian with respect to the metric should not in general be neglected. These results can be particularly relevant for cosmological studies of $f(R,T)$ gravity in which some of the material content of the Universe is modeled as a perfect fluid.

It has been established that the famous three-dimensional Thurston geometries have four intrinsically Lorentzian analogs. We explore these spacetimes in three-dimensional general relativity nonminimally coupled to a scalar field together with electromagnetic matter. We find that three of these spacetimes support electromagnetic radiation, while, the other is partially sourced by a nonnull field and supports gravitational radiation. By addressing this problem we have also found a novel type of gravitational Cheshire effect.

One of the aims of aether scalar tensor theory (AeST) is to reproduce the successes of modified Newtonian dynamics (MOND) on galactic scales. Indeed, the quasi-static limit of AeST achieves precisely this, assuming that the vector field $\overrightarrow{A}$ vanishes and that the so-called ghost condensate can be neglected. The effects of the ghost condensate were investigated in detail in previous studies. Here, we focus on the assumption of a vanishing vector field. We argue that this assumption is not always justified and show how to correctly take into account the vector field, finding that the quasi-static limit depends on a model parameter $m_{\times }$. In the limit $m_{\times }\to 0$, one recovers the quasi-static limit with a vanishing vector field. In particular, one finds a two-field version of MOND. In the opposite limit, $m_{\times }\to \infty$, one finds a single-field version of MOND. We show that, in practice, much of the phenomenology of the quasi-static limit depends only very little on the value of $m_{\times }$. Still, for some observational tests, such as those involving wide binaries, $m_{\times }$ has percent-level effects that may be important.

Light primordial black holes (PBHs) with masses $M_{\mathrm{PBH}}<{10}^9\mathrm{g}$ can interestingly dominate the Universe’s energy budget and give rise to early matter-dominated (eMD) eras before big bang nucleosyntesis (BBN). During this eMD era, one is met with an abundant production of induced gravitational waves (GWs) serving as a portal to constrain the underlying theory of gravity. In this work, we study this type of induced GWs within the context of string-inspired running-vaccuum models (StRVMs), which, when expanded around de Sitter backgrounds, include logarithmic corrections of the space-time curvature. In particular, we discuss in detail the effects of StRVMs on the source as well as on the propagation of these PBH-induced GWs. Remarkably, under the assumption that the logarithmic terms represent quantum gravity corrections in the PBH era, we show that GW overproduction can be avoided if one assumes a coefficient of these logarithmic corrections that is much larger than the square of the reduced Planck mass. The latter cannot characterize quantum gravity corrections, though, prompting the need for revision of the quantization of StRVMs in different than de Sitter backgrounds, such as those characterizing PBH-driven eMD eras. This nontrivial result suggests the importance of light PBHs as probes of new physics.

Among the study of black hole thermodynamics, topology offers a novel approach and perspective for classifying black hole systems. In this work, we explore the thermodynamical topology of the quantum Bañados-Teitelboim-Zanelli (BTZ) black hole by employing the concept of the generalized free energy. To fully characterize the thermodynamics, we introduce two distinct topological numbers. The first one is determined by an expression, denoted by $z$, derived from the free energy. Although it can provide us with some local physical explanations, sufficient physical significance still lacks from a global perspective. On the other hand, the second topological number is based on the entropy expression of the generalized free energy, leading to a more meaningful interpretation of its physical implications. This result highlights the natural choice of entropy as the domain variable for the generalized free energy. Regarding the second topological number, our analysis reveals a topological transition that is associated with the thermodynamical stability of the “cold” black hole state of the quantum BTZ black hole. And the thermodynamical topology of the BTZ black hole and quantum BTZ black hole can be different, which implies a significant impact of quantum effects on thermodynamics. Furthermore, our study suggests the existence of topological numbers beyond the conventional values of $\pm 1$, 0.