We present an application of physics-informed neural networks (PINNs) to the study of $\mathrm{SU}(N_c)$ lattice gauge theories. Our method enables the learning of eigenfunctions and eigenvalues at arbitrary gauge couplings, smoothly moving from the analytically known strong-coupling regime toward weaker couplings. By encoding the Schrödinger equation and the symmetries of the eigenstates directly into the loss function, the network performs an unsupervised exploration of the spectrum. We validate the approach on the single-plaquette U(1) and SU(2) pure-gauge theories, showing that the PINNs successfully reproduce the hierarchy of energy levels and their corresponding wave functions.

In this paper, we propose to test quantum entanglement and Bell nonlocality at an electron-ion collider (EIC). By computing the spin correlations in quark-antiquark pairs produced via photon-gluon fusion, we find that longitudinally polarized photons produce maximal entanglement at leading order, while transversely polarized photons generate significant entanglement near the threshold and in the ultrarelativistic regime. Compared to hadron colliders, the EIC provides a cleaner experimental environment for measuring entanglement through the ${\gamma }^{*}g\to q\overline{q}$ channel, offering a strong signal and a promising avenue to verify Bell nonlocality. This study extends entanglement measurements to the EIC, presenting new opportunities to explore the interplay of quantum information phenomena and hadronic physics in the EIC era.

The mass spectrum of hadrons in magnetic fields features avoided level-crossing structures arising from the mixing of spin eigenstates. In this work, we investigate the impact of level-crossing dynamics of charmonia subjected to time-dependent magnetic fields, where we particularly focus on the occupation probabilities of two or more states as they undergo transitions at avoided crossings. Using a static spectrum of charmonia in magnetic fields, we construct a multichannel Landau-Zener Hamiltonian. Within this framework, we analyze the time evolution under several representative magnetic-field profiles, including linear ramps and Gaussian decays corresponding to single-passage dynamics, as well as Gaussian pulses realizing double-passage dynamics, and compute the occupation probabilities over a wide range of sweep rates and initial conditions. Our results show that nonadiabatic dynamics, including Landau-Zener transitions and Stückelberg interference, strongly influences the occupation probabilities of charmonia. These findings provide new insights into the real-time dynamics of magnetized hadrons and offer useful guidance for future lattice simulation studies.

Utilizing comprehensive experimental data on charmed mesons, we systematically investigate masses of the higher radial and orbital excitations of the $D$ and $D_s$ meson families using the relativistic flux-tube model. Our study employs mass splitting induced by spin-dependent interactions within the j-j coupling scheme. Our predicted masses align well with the experimental measurements for the well-established $D$ and $D_s$ states. However, anomalous resonances such as $D_{s0}(2317)$ and $D_{s1}(2460)$ do not align with conventional meson states within our theoretical framework. We also study strong decays using an effective Lagrangian formalism that combines heavy-quark symmetry with chiral dynamics, focusing on two-body modes into a charmed meson plus a light pseudoscalar ($\pi$, $K$, $\eta$). Using the combined constraints from masses and decay patterns we propose spectroscopic assignments for several recently observed resonances, including $D_2(2740{)}^0$, $D_3^{*}(2750)$, $D_0(2550{)}^0$, $D_1^{*}(2600{)}^0$, $D_1^{*}(2760{)}^0$, $D_J^{*}(3000)$, $D_J(3000)$, $D_2^{*}(3000)$, $D_{s1}^{*}(2860{)}^{\pm }$, and $D_{s3}^{*}(2860{)}^{\pm }$. We also identify $D_{sJ}(3040{)}^{+}$ as a $2P$ excitation with $J^P=1^{+}$. Extending our model, we also calculate the mass spectra of doubly charmed ${\mathrm{\Xi }}_{cc}$ and ${\mathrm{\Omega }}_{cc}$ baryons within the heavy diquark–light quark picture. These theoretical predictions provide crucial guidance for ongoing and future experimental searches for higher radial and orbital excitations in the charmed meson and doubly charmed baryon sectors.

We report a search for ultraheavy dark matter (UHDM) with the CDEX-10 experiment at the China Jinping Underground Laboratory. Using a Monte Carlo framework that incorporates Earth shielding effects, we simulated UHDM propagation and energy deposition in p-type point-contact germanium detectors. Analysis of $205.4\mathrm{kg}·\mathrm{day}$ exposure in the 0.16–4.16 keVee range showed no excess above background. Our results exclude the spin-independent UHDM-nucleon scattering with two cross section scales, with the UHDM mass from ${10}^6$ to ${10}^{11}\mathrm{GeV}$, and provide the most stringent constraints with solid-state detectors below ${10}^8\mathrm{GeV}$.

Results are presented on ${\chi }_{b1,2}(2P)\to \omega \mathrm{\Upsilon }(1S)$ transitions from $e^{+}{e}^{-}\to \mathrm{\Upsilon }(3S)\to \gamma {\chi }_{b1,2}(2P)$ decays. The data were collected with the BABAR detector at the PEP-II asymmetric-energy $e^{+}{e}^{-}$ collider at SLAC. The integrated luminosity of the data sample is $28.0{\mathrm{fb}}^{-1}$, corresponding to $121.3\times {10}^6$ $\mathrm{\Upsilon }(3S)$ decays. Signals of ${\chi }_{b1,2}(2P)$ are observed over a negligible background. Improved precision measurements of branching fractions are obtained. First measurements of the ${\chi }_{b1,2}(2P)$ angular distributions are performed. No evidence is found for the presence of a ${\chi }_{b0}(2P)\to \omega \mathrm{\Upsilon }(1S)$ decay mode.

This paper proposes a novel decoupling limit of the membrane, leading to the ($1+2$)-dimensional classically integrable model originally introduced by Manakov, Zakharov, and Ward. This limit is the large-wrapping regime of a membrane propagating toy background of the form ${\mathbb{R}}_t\times T^2\times G$ subject to scaling limit, where $G$ is a Lie group and the geometry is supported by a four-form flux. Such toy backgrounds can arise from consistent eleven-dimensional supergravity solutions, exemplified by the uplift of the pure Neveu-Schwarz-Neveu-Schwarz ${\mathrm{AdS}}_3\times {\mathrm{S}}^3\times {\mathrm{T}}^4$ background. The scaling limit can be interpreted as a simultaneous small tension and non- or hyperrelativistic limit.

Within the standard framework in which electroweak sphaleron processes relate lepton and baryon numbers, we derive an upper limit on the amplitude of a chiral gravitational-wave background produced prior to the electroweak epoch. This bound is independent of the production time of chiral GWs for superhorizon modes, while it becomes sensitive to the production time for subhorizon modes. For sufficiently high reheating temperatures, the bound becomes significantly more stringent than the conventional big bang nucleosynthesis constraints at frequencies above the MHz scale, thereby providing a powerful and model-independent probe of parity-violating physics in the early Universe.

We present results of field-level inference of the baryon acoustic oscillation (BAO) scale $r_s$ on rest-frame dark matter halo catalogs. Our field-level constraint on $r_s$ is obtained by explicitly sampling the initial conditions along with the bias and noise parameters via the LEFTfield EFT-based forward model. Comparing with a standard reconstruction pipeline applied to the same data and over the same scales, the field-level constraint on the BAO scale improves by a factor of $\sim 1.2–1.4$ over standard BAO reconstruction. We point to a surprisingly simple source of additional information.

In this Letter, I quantify the effects of varying the top Yukawa coupling in the process of the production of three Higgs bosons at the LHC. Modifications of the coupling within experimentally observed ranges have a sizeable impact on the total cross section, but they do not have large effects on the distributions of the invariant mass of the three-Higgs system and other global observables.

We derive a local, crossing symmetric dispersion relation (CSDR) for 2-2 scattering amplitudes with a parametric ambiguity motivated by string theory. Various limits of the parameter lead to the fixed-$t$, fixed-$s$, and other known CSDRs. We also present formulas for higher-subtracted cases. Several examples are discussed for illustration. In particular, for the Veneziano and the Virasoro-Shapiro amplitudes, we derive parametric series representations which manifest poles in all channels and converge everywhere. We then discuss applications of our formalism for bootstrapping weakly coupled gravitational effective field theories. We demonstrate that even in the presence of the graviton pole, one can derive bounds on the Wilson coefficients while working in the forward limit, with the parameter acting as the IR regulator instead. Finally, we derive series representations for multivariable, totally symmetric generalizations of the Veneziano and Virasoro-Shapiro amplitudes that manifest poles in all the variables. This is a first step towards dispersion relations for $n$-particle scattering amplitudes.

The U-dualities of maximally supersymmetric nonchiral supergravity (SUGRA) theories lead to strong constraints on the nonperturbative structure of quantum gravity. In this paper, we determine spin- and pin-lifts of these dualities, which extend this action to fermionic degrees of freedom. Among other things, this allows us to access nonsupersymmetric sectors of these low energy effective field theories in which bosonic and fermionic degrees of freedom are treated differently. We use this refinement of the duality groups, in tandem with the Swampland cobordism conjecture, to predict new codimension-two branes. These are a natural generalization of the recently discovered R7-branes of type II string theories. The first bordism groups for Spin-twisted duality bundles that follow directly from the Abelianization of the duality groups. Viewing the SUGRA theory as the low energy limit of a toroidal compactification of M-theory, winding around these codimension-two defects enacts a reflection around one of the torus directions, which, in the effective field theory, appears as a charge conjugation symmetry. We establish some basic properties of such branes, including determining Bogomol’nyi-Prasad-Sommerfield objects which can end on it, as well as braiding rules and bound states realized by multiple reflection branes.

We present a geometric extension of the Bogomolny-Prasad-Sommerfield (BPS) construction for scalar kinks in ($1+1$) dimensions embedded in static curved spacetimes. By introducing a nonminimal coupling between the scalar prepotential and the extrinsic curvature of the static foliation, the flat-space first-order Bogomolny equation remains exactly valid for arbitrary static backgrounds. As a consequence, the kink profile is unchanged, while the effective potential and vacuum structure acquire a controlled geometric dependence. We show that these curved-space BPS kinks are always linearly stable. However, the existence of the translational zero mode is not guaranteed: its normalizability depends on the competition between the intrinsic length scale of the kink and the asymptotic curvature scale of the geometry. When the geometric scale dominates, the zero mode is removed and the soliton becomes geometrically pinned, despite remaining an exact BPS solution. Explicit realizations in ${\mathrm{AdS}}_2$ demonstrate how different static slicings of the same spacetime lead to qualitatively distinct physical outcomes, ranging from preserved translational invariance to its complete removal by horizons. These results establish geometry as a precise mechanism for controlling solitonic moduli without compromising linear stability.

In this paper, we study frozen states of charged boson stars. These solutions are globally regular and exist in a U(1) gauged scalar field model minimally coupled to gravity for suitable choices of the coupling constants. These configurations are field theoretical realizations of the Mazur-Mottola solution with a de Sitter interior, a black hole exterior and a thin shell that interpolates between the two and replaces the event horizon. We demonstrate that standard electrodynamics is sufficient to find these frozen states, but that the self-interaction of the scalar field is crucial. For a sixth-order self-interaction of the scalar field, solutions exist that possess $k=2n$, $n\in \mathbb{N}$ nodes in the scalar field. The interval in which these nodes exist corresponds to an additional intermediate shell that corresponds to vacuum. Adding Horndeski vector-tensor gravity to the model allows the frozen states to exist without self-interaction though. The frozen states possess one stable and one unstable lightring, the former inside the thin shell, the latter in the black hole exterior.

The dynamics of $\mathcal{N}=1$ supersymmetric gauge theories with matter in adjoint and fundamental representations and the superpotentials given by Arnold’s ADE singularities has been extensively studied in the literature. It was also conjectured that supersymmetric models with $W_{A_k}$, $W_{D_{k+2}}$, and $W_{E_7}$ superpotentials possess a dual description. In this paper, we revisit the analysis of the moduli space of $A_k$ and $D_{k+2}$ models by considering the duality along nilpotent directions on the moduli space. While our analysis provides additional evidence for the duality conjecture in $W_{A_k}$ models, we show that the duality conjecture fails for the $W_{D_{k+2}}$ models.

In nature, some UV features of dynamics are reflected in IR quantities. In fully relativistic theories, this connection can be probed through the analyticity properties of scattering amplitudes, allowing one to understand which IR theories respect the UV assumptions of quantum field theory. The ensuing analyticity bounds can usually be rephrased as the absence of faster-than-light propagation for low-energy excitations. While it is interesting to understand these relations and their IR characterization for theories that have less idealized properties, it is also more difficult to derive analyticity bounds in these cases. For theories that spontaneously break Lorentz symmetry, recent progress was made by considering correlators of conserved currents and their analyticity properties. In this work, we focus on such theories and work to close the gap from the IR side, finding a natural way to express the known analyticity bounds purely in terms of low-energy kinematical quantities. Our analysis shows that the bounds require gapped excitations to have a slower speed than the gapless ones, at least for momenta that are low with respect to the mass gap. These results suggest a way to interpret the UV/IR connection in more complex theories.

We present a theoretical study of the magnetic field generated by a toroidal current loop situated in the equatorial plane of a nonrotating Schwarzschild black hole, based on the dynamics of charged particles. Using the exact general relativistic solution for the magnetic field, we analyze particle motion both analytically and numerically, identifying regions of stable and unstable orbits. In particular, we classify charged particle dynamics into attractive and repulsive Lorentz force configurations and show that in the attractive case, charged particles can occur more frequently near the current loop, forming collective currents that oppose the original current loop magnetic field. We compare the curved spacetime solution to flat spacetime analogs and highlight general relativistic effects such as the existence of the innermost stable circular orbit for charged particles, which sets a lower bound for radiation belt formation. The divergence of the vector potential at the loop location in the idealized infinitesimal loop model is addressed, and we argue that a physically realistic model must consider a finite-width current distribution to avoid unphysical divergences in the effective potential.

Hybrid metric-Palatini gravity unifies the metric and Palatini formalisms while preserving a propagating scalar degree of freedom, offering a compelling route to modified gravity consistent with current observations. Motivated by this success, we consider an extended framework—the hybrid metric-Palatini scalar-tensor (HMPST) theory—in which an additional scalar field $\varphi$ modulates the curvature couplings, enriching the dynamics and enabling nontrivial self-interactions through scalar potentials. We focus on the analytically tractable linear-$f(\widehat{R})$ subclass and study its cosmological, strong-field, and weak-field regimes. In homogeneous and isotropic settings, we identify de Sitter and matter-dominated cosmological solutions describing accelerated expansion and early-Universe behavior. For static, spherically symmetric configurations, the field equations yield analytic solutions generalizing the Janis-Newman-Winicour and Buchdahl metrics, including the Schwarzschild–de Sitter limit. In the weak-field regime, linearized perturbations around Minkowski space lead to Yukawa-type corrections to the gravitational potential, with an effective Newton constant $G_{\mathrm{eff}}$ and post-Newtonian parameter $\gamma$ that recover general relativity for heavy or weakly coupled scalars. These results show that the linear-$f(\widehat{R})$ HMPST subclass provides a consistent and unified description of gravity across cosmological, astrophysical, and Solar System scales, offering a fertile framework for connecting modified gravity to observations and effective field-theoretic extensions.

We discuss photon rings around as well as shadows of Kerr black holes immersed in a swirling spacetime (KBHSU). We find that the spin-spin interaction between the angular momentum of the black hole and the swirling of the background leads to new interesting effects as it breaks the symmetry between the upper and lower hemispheres. We find that a pair of light rings exists for all values of the parameter space. Using a topological argument, we prove that there should be, indeed, two light rings and that, additionally, these light rings are unstable. In comparison to the Schwarzschild black hole immersed in a swirling universe, the light rings typically all possess different radii. Interestingly, as the value of the swirling parameter is increased at fixed angular momentum of the black hole, the two disconnected patches of the ergoregions eventually merge. The light ring at this merger possesses no angular velocity (as measured by an observer at infinity) and is called a light point. To our knowledge, this is the first time the existence of such a light point in a black hole spacetime is reported. Finally, we also present the shadows of KBHSU for various parameter values and observe that, due to the presence of the swirling background, the shadows are twisted.

Thermal distribution functions can only be of the Fermi-Dirac or Bose-Einstein types, whereas distorted spectra encompass any possible deviations from these shapes. It is fruitful to devise parametrizations of these distortions with only a few parameters which depend on the physical system considered. A method proposed by Stebbins consists in describing a distorted spectrum as a sum of thermalized spectra with a distribution of temperatures, the moments of which are the parameters of interest. After revisiting and extending this approach by working at the level of the number density distribution instead of the standard spectrum, we build another method which consists in describing the distorted spectrum by a polynomial modulating a reference thermalized spectrum. The distortion parameters are then the coefficients of a decomposition on a suitable orthonormal polynomial basis. We advocate that the latter is computationally easier and allows to describe a wide range of distortions. With this formalism, we efficiently describe the standard distortions of the cosmological backgrounds of neutrinos and photons, and we obtain model-independent constraints on nonstandard distortions of these cosmological relics.