The production of heavy quarks (charm and beauty) in high-energy hadronic and nuclear collisions provides an excellent testing ground for the theory of strong interactions and validates models based on quantum chromodynamics (QCD). In this work, prompt and nonprompt production of $\mathrm{J}/\psi$ in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$ are studied as a function of the transverse spherocity using pythia8. $\mathrm{J}/\psi$ is reconstructed via its electromagnetic decay to dielectrons and dimuons, in mid- and forward rapidity, respectively. Transverse spherocity, an event-shape observable, is used to distinguish hard-QCD events from the softer, isotropic ones. In pythia8, the production of $\mathrm{J}/\psi$ can be influenced by the average number of multiple parton interactions ($⟨N_{\mathrm{mpi}}⟩$), owing to the underlying events, which have a dominant contribution to particle production at lower transverse momentum. Since transverse spherocity is correlated to $⟨N_{\mathrm{mpi}}⟩$, this can serve as an experimentally accessible tool for event selection to study the underlying QCD processes influencing the prompt and nonprompt $\mathrm{J}/\psi$ production. This study reveals the correlation between heavy-flavor production dynamics and topological event selection in $pp$ collisions using pythia8, whose relevance awaits experimental validation.

We investigate the onset of hyperons in baryonic (diquark) matter in two-color QCD (${\mathrm{QC}}_2\mathrm{D}$) by introducing heavy quark doublets that emulate strange quarks. An even number of flavors is chosen to construct a theory amenable to sign-problem-free lattice Monte Carlo simulations. To explore ${\mathrm{QC}}_2\mathrm{D}$ matter containing both light and heavy quarks, we construct a model in which quarks interact with light-light, light-heavy (hyperonic), and heavy-heavy diquarks via Yukawa couplings. As the quark chemical potential increases, the light diquarks condense first and form baryonic matter, and this onset density can be understood in hadronic terms. In contrast, the onset density of hyperons is substantially higher than that estimated from the hadronic sector of the model. This shift reflects an effective repulsion among baryons induced by the preoccupied light quarks. The Pauli blocking of light quarks suppresses the attractive diquark correlations responsible, in vacuum, for making hyperons lighter than the sum of the constituent light and heavy quark masses. Implications for three-color QCD are also briefly discussed.

We present the complete set of positivity bounds on the Higgs effective field theory (HEFT) at next-to-leading order (NLO). We identify the 15 operators that can be constrained by positivity, as they contribute to $s^2$-growth in the amplitude for longitudinal gauge-Higgs scattering, that is to all possible 2-to-2 scattering processes involving longitudinal gauge bosons, $V_L=W_L^{\pm },Z_L$, and the Higgs boson, $h$. We find two sets of constraints: (i) specific linear combinations of $CP$-even Wilson coefficients (WCs) must be positive, and (ii) the magnitudes of some WCs—including all $CP$-odd ones—must be smaller than products of other $CP$-even WCs. We present our final constraints on the 15 dimensional HEFT space and show how known positivity bounds on the 3 dimensional space of dimension 8 SMEFT can be recovered from them. We find that only about 5% of the parameter space for WCs of HEFT operators at NLO complies with these positivity constraints. Additionally, we obtain double-sided bounds on these WCs by fully exploiting the implications of unitarity and $st$-crossing symmetry. For WCs contributing to the vector boson scattering process our final constraints are in most cases significantly stronger than the experimental ones. For the $V_L{V}_L,hh\to hh$ and $V_L{V}_L,hh\to V_{L}h$ process, there are no reported experimental limits and our theoretical constraints provide the first bounds.

The reduced cross section of the semiexclusive $(l,l^{\prime }p)$ lepton scattering process irrespective of the type of interaction is determined mainly by the bound nucleon momentum distribution in the target and nucleon final state interaction with the residual nucleus. These cross sections can be identified with distorted nuclear spectral functions and therefore, they are similar up to Coulomb corrections for neutrino and electron scattering on nuclei. In this article, we exploit this similarity and use data with precise kinematics and large statistics for semiexclusive electron scattering on an oxygen target to test models employed in the genie neutrino event generator. We find that these models cannot reproduce well the measured reduced cross sections in all allowed kinematic regions and the genie event generator needs to describe better both the nuclear ground states and nucleon final state interaction. The approach presented in this paper provides a great opportunity to better test the accuracy of nuclear models of quasielastic neutrino-nucleus scattering, employed in neutrino event generators.

We search for the $e^{+}{e}^{-}\to \gamma {\chi }_{bJ}$ ($J=0$, 1, 2) processes at center-of-mass energies $\sqrt{s}=10.653$, 10.701, 10.746, and 10.804 GeV. These data were collected with the Belle II detector at the SuperKEKB collider and correspond to 3.5, 1.6, 9.8, and $4.7{\mathrm{fb}}^{-1}$ of integrated luminosity, respectively. We set upper limits at the 90% confidence level on the Born cross sections for $e^{+}{e}^{-}\to \gamma {\chi }_{bJ}$ at each center-of-mass energy $\sqrt{s}$ near 10.746 GeV. The upper limits at 90% confidence level on the Born cross sections for $e^{+}{e}^{-}\to \gamma {\chi }_{b1}$ are significantly smaller than the corresponding measured values for $e^{+}{e}^{-}\to \omega {\chi }_{b1}$ and $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\mathrm{\Upsilon }(2S)$ at $\sqrt{s}=10.746\mathrm{GeV}$.

The presence of a topological susceptibility in the electroweak sector of the Standard Model motivates the existence of a good quality weak axion $a_W$, associated with the spontaneous breaking of $B+L$. Its anomalous couplings and tiny mass, generated from electroweak instantons, render $a_W$ photophobic. We find that the strongest bound on the associated decay constant $f_W$ stems from a loop-induced coupling to electrons, leading to $f_W\gtrsim 1000\mathrm{TeV}$ from stellar cooling. Spontaneous breaking of the Abelian $B+L$ symmetry induces proton decay via higher-dimensional operators controlled by a new physics scale $\mathrm{\Lambda }$. Existing Super-Kamiokande limits on these decay channels constrain the new physics scale to be $\mathrm{\Lambda }\gtrsim {10}^{12}\mathrm{GeV}$. The characteristic channel $p\to e^{+}{a}_W$ and other possible operators mediating interactions with the Standard Model fields yield signals which are not detectable within the allowed parameter space. Future proton decay searches at the next generation of neutrino experiments offer the most promising avenues to test the good qualities of the weak axion paradigm.

Three-dimensional (3D) Carrollian conformal field theories (CFTs) are potential codimension-one holographic duals of 4D asymptotically flat spacetimes that live on the whole of the null boundary. In this paper, we show that the local stress tensor of the 3D Carrollian conformal theory (without any additional sources) constructed in terms of the geometric structure at asymptotic null infinity naturally encodes both the leading and subleading soft graviton theorems. We relate the 3D Carroll stress tensor to the 2D Celestial one and show how the 3D version naturally localizes the nonlocal 2D Celestial stress tensor. We also comment on the relation with stress tensors in relativistic 3D CFTs and connections to the flat limit of AdS/CFT.

We extend the $\kappa$-symmetry analysis of supersymmetric D-brane probes in the ${\mathrm{AdS}}_2\times {\mathbf{S}}^2$ attractor geometry, originally performed by Simons, Strominger, Thompson, and Yin to also include stationary—but nonstatic—worldlines carrying angular momentum along the 2-sphere. We demonstrate that certain special trajectories, with fixed radius and orbital velocity, solve the equations of motion and moreover satisfy a supersymmetry preserving condition, thus defining new $\frac{1}{2}$-BPS configurations. Furthermore, these classical paths are shown to saturate a lower bound for the Hamiltonian generating global time translations, with the corresponding minimal energy depending on a generalized angular momentum vector $\mathit{J}$. The direction of the latter, in turn, determines exactly which supercharges remain unbroken. Our results reveal a richer spectrum of (multiparticle) supersymmetric states in ${\mathrm{AdS}}_2\times {\mathbf{S}}^2$, which can be organized into distinct selection sectors labeled by the conserved $SU(2)$ charges. This construction has direct applications in black hole microstate counting, the analysis of probe dynamics, and ${\mathrm{AdS}}_2/{\mathrm{CFT}}_1$ holography.

We investigate critical phenomena during the gravitational collapse of a massive scalar field under two distinct semiclassical loop quantum gravity (LQG) approaches within spherical symmetry. Numerical simulations reveal that the massive scalar field in both semiclassical frameworks exhibits two distinct types of critical behavior, consistent with the classical scenario. When the scalar field’s mass parameter is small, type II critical phenomena emerge, with the resulting echoing periods and critical exponents precisely matching those obtained in general relativity. In contrast, a large mass parameter triggers type I critical phenomena, where the resulting black holes possess a finite minimum mass. These findings suggest that semiclassical corrections from LQG have a negligible impact on the dynamics of critical collapse.

Topology plays a central role in classifying solitonic configurations in field theories, providing robustness and a nonperturbative label, the so-called topological charge $Q$. In soliton-fermion coupled systems, the relation between the topological charge and the number of zero modes is well established through the index theorem. However, the physical consequences of the sign of the topological charge have remained largely unexplored. In this work, we study fermions in $2+1$ dimensions coupled to skyrmions with target space $\mathbb{C}{\mathrm{P}}^N$, particularly focusing on the backreactions of the fermions and on the sign of the topological charge. We obtain the solutions in a self-consistent manner, which exhibit an asymmetry with respect to the topological charge $\pm Q$ especially in the strong coupling regimes. This asymmetry is caused by the fermionic eigenvalue problem inherent in the self-consistent formulation. Although the Lagrangian is symmetric under $Q\to -Q$, the coupled equations for the skyrmions and anti-skyrmions become inequivalent once fermionic backreaction is taken into account. We demonstrate the mechanism in $\mathbb{C}{\mathrm{P}}^1$ and $\mathbb{C}{\mathrm{P}}^2$ skyrmions, but the analysis is directly extendable for the general $\mathbb{C}{\mathrm{P}}^N$.

Recent efforts have shown that Kantowski-Sachs spacetime provides a useful framework for analyzing perturbations inside a Schwarzschild black hole (BH). In these studies, the adoption of a Hamiltonian formulation offers an insightful perspective. The aim of this work is twofold. First, we revisit and elaborate the results obtained so far in Kantowski-Sachs spacetime, with the focus placed on axial perturbations. In particular, by exploiting the relation between this spacetime and the interior of a nonrotating BH, we consider the extension of those results to the exterior geometry of the BH. In this way, we clarify the relation between the axial perturbative gauge invariants emerging from the canonical analysis and the already well-established axial BH invariants, often referred to as master functions. We do so by providing a unified picture of the Hamiltonian formalism, which does not distinguish, formally, between exterior and interior geometries. The second objective is to explore the role of Darboux transformations, which were found as hidden symmetries in the context of BH perturbations, and their appearance in the Hamiltonian setting. Within this framework, the Hamiltonian formulation provides a clear geometric interpretation and characterization of Darboux transformations within the axial sector, viewing them as the set of canonical transformations between Hamiltonians for axial master functions.

Ultralight boson clouds can form around black holes in binaries through superradiance, and undergo resonant level transitions at certain orbit frequencies. In this work, we investigate the gravitational waves emitted by the clouds during resonant level transitions, and forecast their detectability with future gravitational wave observations. We find that, for scalar fields of mass around ${10}^{-12}\mathrm{eV}$, clouds in stellar mass black hole binaries can radiate gravitational waves around 0.1 Hz during hyperfine level transition, that could be detected with future gravitational wave detectors such as Big Bang Observer, but at a very low event rate. We also consider the clouds in intermediate mass black hole binaries, which can emit milli-Hz gravitational waves during hyperfine level transition. The resulting gravitational waves, however, can hardly be detected with laser interferometer space antenna-like detectors.

We study the linear stability of nonrelativistic Proca stars under generic perturbations. Using a combination of analytic and numerical methods, we demonstrate that, as expected, the ground state is always mode-stable. Additionally, we identify several mode-stable spherically symmetric excited states, including stationary states of constant and radial polarization, as well as multifrequency states in case that the spin-spin self-interaction vanishes. The existence of stable excited states may have implications for spin-1 ultralight dark matter models.

We revisit the problem of gravitational-wave extraction in numerical relativity with gauge-invariant metric perturbation theory of spherical spacetimes. Our extraction algorithm allows the computation of even-parity (Zerilli-Moncrief) and odd-parity (Regge-Wheeler) multipoles of the strain from a ($3+1$) metric without the assumption that the spherical background is in Schwarzschild coordinates. The algorithm is validated with a comprehensive suite of three-dimensional problems including fluid ($f$-modes) and spacetime ($w$-modes) perturbations of neutron stars, gravitational collapse of rotating neutron stars, circular binary black holes mergers and black hole dynamical captures, and binary neutron star mergers. We find that metric extraction is robust in all the considered scenarios and delivers waveforms of overall quality similar to curvature (Weyl) extraction. Metric extraction is particularly valuable in identifying waveform systematics for problems in which the reconstruction of the strain from the Weyl multipoles is ambiguous. Direct comparison of different choices for the gauge-invariant master functions show very good agreement in the even-parity sector. Instead, in the odd-parity sector, assuming the background in Schwarzschild coordinates can minimize gauge effects related to the use of the $\mathrm{\Gamma }$-driver shift. Moreover, for optimal choices of the extraction radius, a simple extrapolation to null infinity can deliver waveforms compatible to Cauchy-characteristic extrapolated waveforms.

We consider a general dark energy (DE) model parametrized by its equation of state (EOS), featuring three free parameters: $w_0$ (the present-day value of the DE EOS), $w_{\beta }$ (quantifying the dynamical nature of the DE EoS), and $\beta$ (governing various dynamical forms of the DE EOS). The key controlling parameter $\beta$ can recover several existing DE models in the literature, such as the Chevallier-Polarski-Linder (CPL) parametrization ($\beta =1$), the logarithmic parametrization (in the limit $\beta \to 0$), and the linear parametrization ($\beta =-1$), alongside generate a class of new DE parametrizations for other values of $\beta$. The resulting DE scenario is constrained using a suite of the latest cosmological probes, including cosmic microwave background (CMB) temperature and polarization anisotropies from three different experiments (Planck 2018 and the Atacama Cosmology Telescope combined with WMAP), CMB lensing, baryon acoustic oscillations from Dark Energy Spectroscopic Instrument Year 2, and PantheonPlus from Type Ia supernovae. Our analyses reveal that stringent constraints on the DE parameters are obtained only when all cosmological probes are combined; otherwise, some parameters remain unconstrained. The present-day value of the DE EOS remains in the quintessence regime according to our results, and no significant evidence for a dynamical DE EOS is found. However, based on the $\mathrm{\Delta }{\chi }^2$ and Bayesian evidence analyses, we observe a mild preference for the present three-parameter DE parametrization over the CPL parametrization when all cosmological probes are taken into account. Nonetheless, the Bayesian evidence difference remains below the threshold for statistical significance according to the revised Jeffreys scale, indicating that both models are effectively equally preferred by the data.

We present a local-to-global cosmological framework in which cosmic acceleration emerges from structure formation in an inhomogeneous Einstein–de Sitter (iEdS) universe, without dark energy. The model exhibits a quasilinear coasting evolution toward an effective Milne state driven by growing inhomogeneities. We test the iEdS model with $H_0=72.5\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$ and ${\mathrm{\Omega }}_{\mathrm{m},0}=0.272$ using cosmic microwave background, baryon acoustic oscillation, and type Ia supernova data. The iEdS model fits the data comparably to $\mathrm{\Lambda }\mathrm{CDM}$ and resolves the $H_0$ tension, while yielding a cosmic age $t_0\simeq 13.67\mathrm{Gyr}$ consistent with globular-cluster estimates.

Models of cosmic inflation generically predict a weak but potentially detectable amount of primordial non-Gaussianity (PNG), which can be used to obtain insights into the degrees of freedom during inflation and their interactions. The simplest types of PNG are the local and nonlocal (equilateral and orthogonal) shapes of the primordial three-point correlators, which are predicted by models with multiple light fields and derivative interactions in single-field inflation, respectively. In this paper, we place constraints on local, equilateral, and orthogonal non-Gaussianities using the power spectrum and bispectrum extracted from the first public release of the Dark Energy Spectroscopic Instrument (DESI). Our analysis makes use of higher-order clustering information through a consistent effective field theory (EFT) model for both the power spectrum and bispectrum at one-loop order. Using robust scale cuts where the EFT description is valid, we find the following constraints on PNG amplitudes: $f_{\mathrm{NL}}^{\mathrm{loc}}=-0.1\pm 7.4$, $f_{\mathrm{NL}}^{\text{equil}}=719\pm 390$, $f_{\mathrm{NL}}^{\mathrm{orth}}=-200\pm 100$ (at 68% confidence level). Nonlocal PNG constraints can be further improved by combining high-redshift DESI with legacy BOSS data and using simulation-based priors on bias parameters, yielding the strongest large-scale structure constraints to date $f_{\mathrm{NL}}^{\text{equil}}=200\pm 230$, $f_{\mathrm{NL}}^{\mathrm{orth}}=-24\pm 86$. Our constraint on $f_{\mathrm{NL}}^{\mathrm{loc}}$ is competitive with the cosmic microwave background (CMB) limit; the combination gives $f_{\mathrm{NL}}^{\mathrm{loc}}=-0.0\pm 4.1$, 18% stronger than the CMB-only result, which represents the strongest bound on multifield inflation yet obtained.

The big bang quantum cosmology model introduces the trace $J$ of the Schouten tensor as a form of dynamic dark energy. Together with cold dark matter (CDM), these components form the so-called $J\mathrm{CDM}$ cosmology model, proposed by van Putten [J. High Energy Astrophys. 45, 194 (2025)], which offers a potential resolution to the Hubble tension. We derive the constraints on the $J\mathrm{CDM}$ cosmology model, utilizing early- and late-time cosmological data including cosmic microwave background, baryon acoustic oscillations released by the Dark Energy Spectroscopic Instrument (DESI), cosmic chronometers, and type Ia supernovae. For a flat universe, the $J\mathrm{CDM}$ model yields $H_0=66.95\pm 0.51\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$ and ${\mathrm{\Omega }}_m=0.3419\pm 0.0065$, results that are consistent with early-Universe observations but exhibit a higher ${\mathrm{\Omega }}_m$ compared to the $\mathrm{\Lambda }\mathrm{CDM}$ model. In the case of a nonflat universe, $J\mathrm{CDM}$ favors a slightly curved geometry with ${\mathrm{\Omega }}_k=0.0154\pm 0.0027$, leading to $H_0=69.13\pm 0.56\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$ and ${\mathrm{\Omega }}_m=0.3477\pm 0.0074$. The increase in $H_0$ in the nonflat scenario suggests a geometric degeneracy between spatial curvature and $H_0$. We also investigate the internal inconsistencies present in DESI data and evaluate their impacts on cosmological parameter constraints. Our analysis shows that while the $J\mathrm{CDM}$ model, which is constructed from first principles without free parameters beyond those of $\mathrm{\Lambda }\mathrm{CDM}$, agrees excellently with late-time cosmology, it struggles to simultaneously match early-Universe observations in a fully self-consistent manner.

Cosmological studies of the Lyman-$\alpha$ (Ly-$\alpha$) forest typically constrain parameters using two-point statistics. However, higher-order statistics, such as the three-point function (or its Fourier counterpart, the bispectrum) offer additional information and help break the degeneracy between the mean flux and power spectrum amplitude, albeit at a significant computational cost. To address this, we extend an existing highly informative compression of the bispectrum, the skew spectra, to the Ly-$\alpha$ forest. We derive the tree-level bispectrum of Ly-$\alpha$ forest fluctuations in the framework of effective field theory directly in redshift space and validate our methodology on two mock datasets: (i) synthetic three-dimensional (3D) Ly-$\alpha$ fields using second-order perturbation theory and (ii) large Ly-$\alpha$ forest mocks constructed from the $N$-body simulation suite abacussummit. We measure the three-dimensional anisotropic cross-spectra between the transmitted flux fraction and all quadratic operators arising in the bispectrum, yielding a set of 26 skew spectra. Using idealized 3D Gaussian smoothing ($R=10h^{-1}\mathrm{Mpc}$), we find good agreement ($1-2\sigma$ level based on the statistical errors of the mocks) with the theoretical tree-level bispectrum prediction for monopole and quadrupole up to $k\lesssim 0.17h{\mathrm{Mpc}}^{-1}$. To enable the cosmological analysis of Ly-$\alpha$ forest data from the currently observing Dark Energy Spectroscopic Instrument (DESI) and future spectroscopic surveys, where we cannot do 3D smoothing, we use a line-of-sight smoothing and introduce a new statistic, the shifted skew spectra. These probe nonsqueezed bispectrum triangles and avoid locally applying quadratic operators to the field by displacing one copy of the field in the radial direction. Using a fixed displacement between two points of $40h^{-1}\mathrm{Mpc}$ (and line-of-sight smoothing $10h^{-1}\mathrm{Mpc}$) yields a similar agreement with the theory prediction. For the special case of correlating the squared (and displaced) field with the original one, we analytically forward model the window function making this approach readily applicable to DESI data.

Axion dark matter thermalizes by gravitational self-interactions and forms a Bose-Einstein condensate. We show that the rethermalization of the axion fluid during the initial collapse of large scale overdensities near cosmic dawn transports angular momentum outward sufficiently fast that black holes form with masses ranging from approximately ${10}^5$ to a few times ${10}^{10}{M}_{\odot }$. This conclusion holds for QCD axions and for axionlike particles of mass larger than ${10}^{-16}\mathrm{eV}/c^2$.