In this work, we study the ${\mathrm{\Omega }}_c$ baryon spectrum up to the $2P$ excitations within a semirelativistic constituent quark potential model, where the mixing between different configurations with the same spin-parity numbers is dynamically considered. Furthermore, the strong decay properties for the excited ${\mathrm{\Omega }}_c$ states are evaluated within an improved chiral quark model by including the relativistic correction term. In a unified framework, we provide a reasonable explanation of the widths, masses, and mass splittings, for the newly observed ${\mathrm{\Omega }}_c$ resonances ${\mathrm{\Omega }}_c(3000)$, ${\mathrm{\Omega }}_c(3050)$, ${\mathrm{\Omega }}_c(3065)$, ${\mathrm{\Omega }}_c(3090)$, ${\mathrm{\Omega }}_c(3120)$, ${\mathrm{\Omega }}_c(3185)$, and ${\mathrm{\Omega }}_c(3327)$. It is found that the configuration mixing is crucial for understanding the strong decay properties and mass splittings, while the relativistic correction term of the strong transition operator plays an important role in the states dominated by the radial excitations. We expect our study can provide useful references for establishing a more abundant ${\mathrm{\Omega }}_c$ spectrum.

The enhancement of the baryon production relative to mesons in small-collision systems is considered a breakthrough result of the Large Hadron Collider since a similar effect in heavy-ion collisions is understood by invoking the formation of the strongly interacting quark-gluon plasma. In this paper, a baryon enhancement is reported for $p_{\mathrm{T}}^{\mathrm{ch},\mathrm{jet}}>15\mathrm{GeV}/c$ jets produced in pp collisions at $\sqrt{s}=13\mathrm{TeV}$ simulated with pythia8. The effect can be explained as a transition between quark-initiated jets (low jet multiplicities) to gluon-initiated jets (high jet multiplicities). The present result contributes to a deeper understanding of the multiplicity dependence of baryon enhancement across different collision systems.

We employ machine learning techniques to estimate the amount of information contained in three Krylov-space observables: the spread complexity $C(t)$, the discrete Wigner negativity $N(t)$, and the normalized negativity $\chi (t)=N(t)/|S(t)|$, where $S(t)$ is the survival amplitude. We study thermofield-double evolutions on Gaussian unitary ensemble (GUE), Gaussian orthogonal ensemble (GOE), and Poisson spectra, and on the integrable $SL(2,R)$ Krylov chain of a two-dimensional conformal field theory (CFT) primary with Lanczos coefficients $b_n=\alpha \sqrt{n(n+2h-1)}$. To introduce chaos we add a GUE random matrix to the integrable chain, $H(ϵ)=H_{SL(2,R)}+ϵR_0{W}_{\mathrm{GUE}}$, where $R_0$ is its spectral half-width. Either $C(t)$ or $N(t)$ alone determines the thermofield temperature, with $R^2\simeq 0.999$. However, neither can reconstruct the fine structure of the spectral form factor. In the integrable sector all three observables carry the same information. When we turn on chaos an asymmetry appears: $\chi$ predicts $C$ better than $C$ predicts $\chi$. This gap grows from $+0.33$ to $+0.77$, while the same gap for the raw negativity decays to zero. Thus we conclude the extra information comes from the survival amplitude and $\chi (t)$ carries it while $C(t)$ can still be recovered from $\chi (t)$. We derive a lower bound on this gap, set by the fraction of the variance of $\chi$ that comes from $S$.

We consider off-diagonal asymptotic series for integral kernels of functions of Laplace-type operators on curved backgrounds. These expansions are obtained by applying integral transforms to the DeWitt series for the heat kernel of the corresponding operator and thus represent a DeWitt-type series in the heat kernel coefficients and some hypergeometric-type functions of the Synge world function (which we call basis kernels). Basis kernels of certain class of operator functions were found previously in terms of $N$-fold Mellin-Barnes integrals. In this paper, we study series representations of the corresponding Mellin-Barnes integrals in both nonresonant and resonant cases and suggest a physical interpretation for the emerging series, which is related to the UV and IR properties of operator functions.

The recent gravitational-wave detection GW250114 by the LIGO-Virgo-KAGRA (LVK) Collaboration provides unprecedented opportunities for precision tests of general relativity (GR) through black hole ringdown. In this study, we provide the first bounds on theory-agnostic deviations from the Teukolsky equation as described by the beyond-Teukolsky formalism. It directly connects deviations in the perturbation equations on the level of the effective potential in the Teukolsky equation with changes in the quasinormal mode (QNM) spectrum. We incorporate information on the final mass and spin from a full LVK inspiral-merger-ringdown analysis as parametrized priors in our analysis, reflecting theoretical uncertainties. Using publicly available LVK posterior information on agnostic damped sinusoid parameters, we then demonstrate how much beyond-Teukolsky potentials can be constrained. The high signal-to-noise ratio (SNR) allows us to avoid the expensive full Bayesian analysis of all parameters and to work directly with a simplified likelihood for the fundamental QNM only. This strategy is promising for future events with even higher SNR and allows, in principle, for a quick and simple test of GR without performing the full data analysis procedure, and provides a basis for complementary theory-specific tests. We report that current bounds on deviation parameters are in agreement with the Teukolsky equation.

Standard pregeometric mechanisms reproduce the $\mathrm{\Lambda }\mathrm{CDM}$ model but lack a natural source for inflation. We propose a mechanism for the emergence of scalar-coupled topological terms by extending the Lie algebra of a MacDowell-Mansouri model to a Lie algebroid. These terms are commonly regarded as a source for cosmological inflation in effective string actions. With an additional constraint on torsion imposed, the theory reduces to a scalar-tensor theory belonging to the Horndeski class, and reproduces inflationary dynamics that meet existing constraints (Planck/BICEP/Keck and GW170817).

Motivated by their common condensed-matter inspiration and their shared aim of reconciling MOND-like phenomenology on galactic scales with particle dark matter on larger scales, we investigate the relation between Superfluid Dark Matter (SFDM) and Bose-Einstein Condensate Dark Matter (BECDM). Since SFDM is formulated in the Newtonian regime whereas BECDM is fully relativistic, we first show that the MONDian formulation of SFDM arises as the Newtonian, low-acceleration limit of a RAQUAL theory in the Einstein frame. We then transform its covariant interaction sector to the Jordan frame and compare it with BECDM. The phonon–baryon interaction of SFDM maps onto the BECDM derivative coupling to the Einstein tensor, supplemented by a small nonminimal coupling to the Ricci scalar. The interaction sectors are therefore equivalent up to a linear perturbation of the Einstein–Hilbert term. Their kinetic sectors, however, remain inequivalent: the standard quadratic kinetic term of BECDM cannot be mapped onto the nonanalytic kinetic term required by SFDM. The two models are consequently related but not dynamically equivalent. This mapping provides a covariant interpretation of the SFDM interaction and clarifies which theoretical properties can be transferred between the two frameworks.

We present CLASSIER-DDM, an extension of the Boltzmann solver CLASSIER that implements the decaying dark matter (DDM) model via its integral-equation approach. The code handles generic two-body decays of a dark matter particle into two lighter decay products with arbitrary masses, naturally encompassing both massless (dark radiation) and massive (warm) decay products, with their perturbations evaluated via integral equations solved iteratively. We describe the numerical implementation in detail, including the background evolution, the iterative perturbation evolution, and a small-scale analytic approximation. A modest number of iterations is sufficient to achieve sub-0.1% convergence in the matter power spectrum and the cosmic microwave background lensing power spectrum across the observationally relevant parameter space. We find that one hundred momentum bins for the decay product perturbations are sufficient to achieve $\mathcal{O}(0.1\%)$ accuracy in the matter power spectrum today up to $k\sim 3{\mathrm{Mpc}}^{-1}$. The code achieves $\mathcal{O}(1\min )$ runtimes per evaluation, requiring neither a Boltzmann hierarchy nor any fluid approximation, making parameter estimation with the DDM model numerically tractable. We also discuss the impact of DDM on cosmological observables, focusing on the case of two massive decay products. This work further establishes the integral-equation approach as a versatile and efficient framework for modeling noncold relics in cosmological perturbation theory.

In the most general formulation of gravity, the metric and connection are independent degrees of freedom, and the connection may include torsion and nonmetricity (or distortion, collectively) degrees of freedom, resulting in a huge number of possible dynamical fields. However, most fields are either nondynamical or extremely heavy and the general relativity is recovered at low energy. We find a unique naturally light vector- or scalarlike distortion field, which can be dynamical and have phenomenological implications. In particular, a light scalar particle that mixes with the Higgs boson naturally appears.

Accurate modeling of small-scale redshift-space clustering is crucial for full-shape redshift-space distortion (RSD) analyses, where satellite galaxies contribute to one-halo terms and Finger-of-God distortions. We investigate halo reconstruction based on the cylinder grouping method of Okumura et al., Mon. Not. R. Astron. Soc. 469, 459 (2017), which selects an effective halo center tracer from the observed galaxy distribution, and how it impacts cosmological parameter inference. Using luminous red galaxy mock catalogs from the AbacusSummit simulations at $z=1.1$, we perform effective field theory (EFT)-based full-shape modeling of the power spectrum of the reconstructed-halo sample. We show that the dominant reconstruction-induced systematics can be described and incorporated within the standard EFT framework. In particular, a simple multipole-dependent rescaling inferred directly from the data on large scales captures the dominant effect, while residual small-scale changes are absorbed by the standard counterterm and stochastic sector, without introducing additional reconstruction-specific parameters. The reconstructed-halo sample yields unbiased constraints on cosmological parameters, including the growth rate $f{\sigma }_{s8}$ and Alcock-Paczynski parameters. Compared to the galaxy sample, it enables both improved robustness and increased statistical precision: at the fiducial limit of $k_{\max }=0.2h{\mathrm{Mpc}}^{-1}$, the uncertainty on $f{\sigma }_{s8}$ is reduced by more than 20%, while the high-$k_{\max }$ diagnostics show comparatively stable goodness of fit and nuisance parameters.

We introduce a density-level pivot construction for the Chevallier–Polarski–Linder parametrization by defining the normalized dark energy density $f_p\equiv f(a_p)$ and the equation of state ${\omega }_p\equiv \omega (a_p)$ at an optimized pivot scale factor $a_p$. This reparametrization leaves the underlying cosmology unchanged and allows the two models to be compared using parameters with a direct physical interpretation at the epoch where the data are most sensitive. Accordingly, following the DESI DR2 results, we compare a newly proposed $f_a{f}_b\mathrm{CDM}$ parametrization, based on a second-order Taylor expansion of the normalized dark energy density, with the standard ${\omega }_0{\omega }_a\mathrm{CDM}$ model. In particular, we constrain the original and pivoted parametrizations using the compressed cosmic microwave background, DESI DR2 baryon acoustic oscillations, cosmic chronometers, and $\mathrm{Pantheon}+\text{Type}$ Ia supernovae data, with the SH0ES prior imposed on $H_0$. We find that applying the same density-level pivot prescription to the ${\omega }_0{\omega }_a\mathrm{CDM}$ model substantially reduces the correlation between its dark energy parameters and provides less correlated constraints in the pivot variables. The statistical comparison shows that this model remains favored over the Taylor expansion of the dark energy density, even when both models are analyzed in the optimized parameter basis. Moreover, the pivoted Chevallier–Polarski–Linder parametrization accurately reproduces the background evolution of quintessence models, providing a reliable phenomenological approximation to the underlying dark energy dynamics, better than the $f_a{f}_b\mathrm{CDM}$ model. We conclude that changing the parameter basis improves the performance of the ${\omega }_0{\omega }_a\mathrm{CDM}$ model, which emerges as the most suitable framework to describe the dark energy sector within the class of models considered here.

Nuclear metamodels—phenomenological parametrizations of the energy of nuclear matter—are convenient tools to explore the space of realistic neutron star configurations constrained by astrophysical and nuclear data. While much recent work has focused on composition-agnostic barotropic models, the metamodel approach is designed to describe the composition dependence of the relevant thermodynamic potential. We revise a previously proposed nonrelativistic metamodel by introducing a more controlled high-density behavior, improving both its causal properties and its accuracy in reproducing the pressure and the $\beta$-equilibrium composition of microscopically motivated equations of state. Since asymptotic causality is enforced by construction, the fraction of discarded models due to superluminal sound speeds is substantially reduced, facilitating metamodel-based explorations of equilibrium neutron star configurations. We further assess our framework by performing a Bayesian inference of neutron star properties beyond standard observables such as masses and radii, exploiting the metamodel’s ability to probe composition-dependent quantities including the dUrca threshold and the Ledoux criterion for g-mode stability.

The cosmic dawn 21-cm signal is a highly sensitive probe of any process which injects energy into the intergalactic medium, enabling novel searches for anomalous energy injection through dark matter interactions. In addition to modifying the global 21-cm signal, these processes would leave distinct imprints on the frequency-resolved 21-cm power spectrum with a morphology jointly set by the time and spatial dependence of energy emission and absorption. In this work, we extend the DM21cm code package, which models the effects of spatially inhomogeneous energy emission and deposition on 21-cm cosmology, to study three well-motivated scenarios which 21-cm measurements are particularly well suited to probe dark matter annihilation through $p$-wave processes, the Hawking radiation of light primordial black holes, and energetic emission from accreting solar-mass primordial black holes. We project sensitivities to each of these scenarios, demonstrating that leading or near-leading sensitivity to each can be achieved through 21-cm probes. We also make public our updates to the DM21cm code package that enable it to accommodate energy injection processes for general continuum spectra with arbitrary spatial and temporal dependence in an accompanying release.

We formulate the dissipation due to sound-wave emission from a Keplerian binary embedded in a homogeneous Newtonian fluid background at rest in the binary center-of-mass frame within linear perturbation theory. Rather than starting from the local wake force, we treat the binary as a localized periodic mass source and compute the sound-wave fluxes carried away by the medium. The time-averaged energy, linear-momentum, and angular-momentum fluxes are obtained from Noether currents of the fluid perturbations. For a classical inviscid barotropic Newtonian fluid, retaining the self-gravity of density perturbations while adopting the Jeans prescription, we derive explicit flux formulas for circular and eccentric binaries with arbitrary mass ratio. This formulation also clarifies the ultraviolet behavior of point sources: in a nondispersive fluid, the harmonic sum becomes cutoff-sensitive precisely when at least one component becomes supersonic. We examine explicitly how finite source size removes this divergence using a uniform-sphere model and relate the resulting regularization to a corresponding effective harmonic cutoff. The associated secular eccentricity evolution exhibits circularization in the subsonic regime when the fluid self-gravity is sufficiently weak but can change sign outside this regime, with eccentricity growth in the strictly supersonic UV limit. For a Schrödinger-Poisson quantum fluid, quantum pressure instead softens the high-frequency contribution and renders the point-source fluxes UV finite within the nonrelativistic regime; our numerical results further indicate eccentricity growth due to sound radiation over the parameter space explored. Finally, we translate orbital-decay measurements of two binary pulsars into order-of-magnitude bounds on the homogeneous quantum-fluid density surrounding each system.

Low eccentricity, short orbital period pulsar companions may provide a probe to study uniquely dense and stable exoplanet internal compositions due to the potentially high orbital evolution they experience caused by strong gravitational tides. We model the tidal characteristics such as apsidal motion constants, orbital precession, and tidal deformability for a variety of equations of state to be compared with values recovered via pulsar timing for a sample of two systems: PSR J1719-1438b and PSR $\mathrm{J}0636+5128\mathrm{b}$. With more time observing these companions through pulsar time of arrival measurements and the James Webb Space Telescope (JWST) enabling improved constraints on companion parameters, it may be possible to use this method in the future to improve limits on their chemical and structural compositions and provide more information on their unique history and formation.

We examine neutrino evolution in astrophysical environments where the neutrino flux is very large, including core-collapse supernovae and neutron star mergers. In these environments, the neutrino-neutrino and neutrino-antineutrino interactions are crucial. We include nonforward scattering of neutrinos and antineutrinos in a semiclassical treatment. Because of the large scale of neutrino momenta (2–10 MeV), the quantum evolution problem can be treated as a sum over incoherent paths in the momentum and flavor of each neutrino. The phases between different neutrinos are essentially random because of the large kinetic terms. Momentum is conserved at each vertex, and important flavor symmetries are retained. Dynamics in the many-body neutrino system enable rapid equilibration in the energy and angular distributions of all flavors, and an equilibration of products of neutrino and antineutrino densities for each flavor at either large or zero background matter density. We also describe the evolution at moderate densities where the mass eigenstates differ for neutrinos and antineutrinos, and with time-varying background matter densities. The evolution maintains relevant symmetries and reduces to standard Mikheyev-Smirnov-Wolfenstein oscillations in the appropriate limits. The rapid equilibration in energy and flavor can significantly impact energy deposition and nucleosynthesis in high-flux astrophysical environments, and potentially flavor energy relations in terrestrial supernovae neutrino observations.

We present a combined analytical and numerical study of the effective action of field theory cosmic strings in the Abelian-Higgs model in flat space. Starting directly from the underlying solitonic field theory description, we provide a systematic derivation of the low energy effective action and present evidence for the absence of nontrivial curvature correction terms when only the translational Goldstone modes are retained. Using this framework, we extend the effective theory to include higher energy fluctuations of the soliton profile, which map to massive degrees of freedom propagating on the worldsheet. We show that the leading curvature contribution enters only through the coupling between these massive modes and the worldsheet Ricci scalar. We validate the resulting effective theory via lattice simulations of the full field theory equations of motion in flat space, implemented with adaptive mesh refinement to capture the string dynamics across different scales. The numerical simulations confirm the dynamics obtained using the effective action in its validity range. Furthermore, they also demonstrate the existence of the predicted parametric instability of excited strings that drives the transfer of energy from massive excitations to the Goldstone sector.

We investigate high-energy photon production from $2\leftrightarrow 2$ processes in a quark-gluon plasma by evaluating the imaginary part of the two-loop photon self-energies in thermal QCD. Working in the imaginary-time formalism, we derive analytical expressions for the leading-logarithmic and beyond-leading-logarithmic contributions to the photon production rate from $2\leftrightarrow 2$ processes. We retain the full Fermi-Dirac and Bose-Einstein statistical factors and compare the resulting Compton and annihilation rates with those obtained from kinetic theory and the closed-time-path formalism. The summed rates agree with the corresponding established results, providing a nontrivial consistency check of the calculation. Furthermore, when we consider the Maxwell-Boltzmann distribution for incoming particles, we find that quantum corrections are absent in the individual $2\leftrightarrow 2$ processes. However, the total rate agrees with that of full statistics.

We present a systematic study of the spacelike electromagnetic form factors of the ground-state singly charmed baryons, ${\mathrm{\Sigma }}_c$ (${\mathrm{\Sigma }}_c^{++},{\mathrm{\Sigma }}_c^{+},{\mathrm{\Sigma }}_c^0$) and ${\mathrm{\Lambda }}_c^{+}$, within a covariant quark-diquark model. Based on this framework, we obtain their magnetic moments as well as electric charge and magnetic moment radii. Such observables are important to understand the internal structure and the inner dynamics of these heavy baryon states. Our theoretical calculations are in qualitative agreement with available lattice QCD results of ${\mathrm{\Sigma }}_c^{++}$ and ${\mathrm{\Sigma }}_c^0$ baryons. We also discuss the mechanism behind the dependence of the numerical results on the charm quark and light diquark. A key finding is that the electric form factors of the singly charmed baryons fall off much more slowly with momentum transfer $Q^2$ than that of the proton, indicating a more compact electric charge distribution, which is attributed to the heavy charm quark acting as a localized core. More importantly, we observe a striking difference in the magnetic structure: while the magnetic form factors of ${\mathrm{\Sigma }}_c$ are dominated by the light axial-vector diquark, those of ${\mathrm{\Lambda }}_c^{+}$ are unexpectedly governed by the charm quark due to the vanishing contribution of the scalar diquark. This highlights the decisive role of the light-diquark spin configuration in determining the magnetic properties. Finally, using an empirical asymptotic relation connecting the spacelike and timelike regions, we predict the total cross section for $e^{+}{e}^{-}\to {\mathrm{\Sigma }}_c{\overline{\mathrm{\Sigma }}}_c$. Our findings can be tested at existing facilities including the BESIII, Belle II and LHCb, as well as the proposed Super Tau-Charm Facility.