The twist-2 distribution amplitude of the $\varphi$-meson has attracted considerable interest due to its unique properties. In this work, we construct the transverse leading-twist light-cone distribution amplitude ${\varphi }_{2;\varphi }^{\perp }(x,{\mu }_0)$ of the $\varphi$-meson using the light-cone harmonic oscillator model, in which a parameter $B_{2;\varphi }^{\perp }$ dominantly controls its longitudinal distribution. To explicitly isolate different twist contributions, we employ the right-handed chiral correlator for the QCD light-cone sum rules calculation of $D_s^{+}\to \varphi$ decays, and further, we get the branching fraction, $\mathcal{B}(D_s^{+}\to \varphi e^{+}{\nu }_e)=(2.271_{-0.243}^{+0.291})\times {10}^{-2}$ and $\mathcal{B}(D_s^{+}\to \varphi {\mu }^{+}{\nu }_{\mu })=(2.250_{-0.240}^{+0.287})\times {10}^{-2}$, where errors are squared average of the mentioned error sources. Furthermore, we have extracted the Cabbibo-Kobayashi-Maskawa matrix element $|V_{cs}|=0.975_{-0.066}^{+0.067}$ with improved precision through the analysis. Finally, we calculated the polarization parameter and asymmetry parameter for the $D_s^{+}\to \varphi$ decays.

We present the first calculation of next-to-leading order (NLO) factorized QED and QCD contributions to the short-distance hard coefficients of inclusive lepton-hadron deep inelastic scattering (DIS) in a joint QED and QCD factorization approach. Unlike the traditional radiative correction approach to handle the collision-induced QED contributions to DIS, QED radiation from all charged leptons and quarks are treated equally, and their collinear sensitivities are systematically factorized into corresponding universal lepton and parton distribution functions. We demonstrate that the NLO factorized short-distance QED contribution is completely infrared safe and calculable without the need of any parameters other than the standard factorization scale in the same way as the factorized short-distance QCD contribution. We discuss the potential impact of this joint factorization approach on the extraction of partonic information from lepton-hadron DIS.

We propose a two-component dark matter (DM) scenario by extending the Standard Model with two additional $SU(2{)}_L$ doublets, one scalar, and another fermion. To ensure the stability of the DM components, we impose a global ${\mathcal{Z}}_2\times {\mathcal{Z}}_2^{\prime }$ symmetry. The lightest neutral states for both the scalar and fermion, which are non-trivially transformed under the extended symmetry, behave as stable two-component DM candidates. While single components are underabundant due to their gauge interactions, in a mass region between $m_W$ and 525 GeV for the scalar and a mass below 1200 GeV for the fermion, and the fermion DM conflicts with direct detection limits over the whole parameter space, having two components helps to saturate relic density in the regions with under-abundance. Compliance with direct detection constraints leads to two options, either introducing dim-5 effective operators, or embedding the scenarios into a complete UV theory, which reproduces a type II seesaw model, thus naturally including neutrino masses. We analyze the consequences of this scenario at the LHC.

We perform a coupled-channels study of the $bb\overline{c}\overline{c}$ and $bc\overline{b}\overline{c}$ tetraquark systems in a molecular approach using a constituent quark model which has been widely used to satisfactorily describe a broad range of properties of heavy quark hadron systems, either conventional or exotic. Within a molecular framework, the interaction in the heavy quark sector is governed by gluon exchange or confinement forces that are inherently color-dependent. While the $B_c{B}_c$ system contains two identical quarks, enabling stronger interactions via exchange diagrams, the forces in the $B_c{\overline{B}}_c$ and $(c\overline{c})-(b\overline{b})$ systems are expected to be significantly weaker. Consequently, the theoretical and experimental analysis of $B_c^{(*)}{B}_c^{(*)}$, $B_c^{(*)}{\overline{B}}_c^{(*)}$, and charmonium-bottomonium bound structures could play a crucial role in clarifying the dominant mechanisms responsible for the formation of fully heavy tetraquarks. For the $bb\overline{c}\overline{c}$ tetraquark sector, we find several resonance states with different spin-parity quantum numbers. These resonances are characterized by their proximity, but not too close, to the $B_c^{(*)}{B}_c^{(*)}$ thresholds and their large total decay widths, indicating strong decay channels. In contrast, our analysis of the $bc\overline{b}\overline{c}$ tetraquark sector reveals no bound states, virtual states, or resonances; suggesting that tetraquark states of the $(c\overline{c})-(b\overline{b})$ or $B_c^{(*)}{\overline{B}}_c^{(*)}$ molecular type are unlikely to be formed, within our model assumptions.

Motivated by the recent BESIII Collaboration measurements of the decay $D^{+}\to {\pi }^{+}\eta \eta$, we investigate this process by considering the contribution from the resonance $a_0(980)$, which is generated by $S$-wave pseudoscalar meson-pseudoscalar meson interaction, and the contribution from the intermediate scalar meson $f_0(1370)$. Our results could give a good description of the ${\pi }^{+}\eta$ and $\eta \eta$ invariant mass distributions, which implies that the contribution from the intermediate $f_0(1370)$, neglected in BESIII analysis, could play a role in this process. Furthermore, the predicted Dalitz plots are also consistent with the BESIII measurements. The more precise measurements about this process in the future could shed light on the mechanism of this process and the properties of $f_0(1370)$ and $a_0(980)$.

We present a comprehensive investigation of the mechanical properties of the ${\mathrm{\Omega }}^{-}$ baryon by analyzing its gravitational form factors (GFFs) within the framework of QCD sum rules. These form factors encode rich information about the internal structure of hadrons and offer deep insights into the dynamics that govern their stability. The spin-$3/2$ nature of the ${\mathrm{\Omega }}^{-}$ baryon manifests in its gravitational form factors as intricate multipole structures, which encapsulate higher-order deformations and demonstrate the influence of intrinsic spin on internal dynamics. We extract the GFFs of the ${\mathrm{\Omega }}^{-}$ baryon and apply their specific multipole combinations, gravitational multipole form factors (GMFFs), to quantify key mechanical observables—including energy density, angular momentum, pressure and shear force distributions, mass and mechanical radii, and D-terms—associated with different multipole orders. Notably, this work provides the first determination of several of these observables, such as the mechanical radii and the quadrupole contributions to the pressure and shear force distributions. Our analysis shows that the quadrupole contributions to the mechanical properties are generally subdominant compared to those from the monopole component. We further investigate the mechanical stability of the ${\mathrm{\Omega }}^{-}$ through a multipole analysis of its internal force distributions. These results enhance our understanding of the mechanical structure of spin-$3/2$ hadrons and provide useful benchmarks for future theoretical and lattice QCD studies.

We develop a novel holographic dictionary for the thermodynamics of black holes with Lifshitz and hyperscaling violating asymptotics, generalizing the dictionary for anti—de Sitter black holes. Using our dictionary we show that the holographic Euler equation is dual to a generalized Smarr formula for these black holes, and we find a precise match between the extended bulk and boundary first law. Notably, the dictionary for the central charge appearing in the Euler relation depends on the hyperscaling violating parameter, but not on the Lifshitz dynamical exponent.

There exist several distinct phenomenological models to generate neutrino masses. We explore which of these models can consistently be embedded in a quantum theory of gravity and matter. We proceed by invoking a minimal number of degrees of freedom beyond the Standard Model. Thus, we first investigate whether the Weinberg operator, a dimension-five operator that generates neutrino masses without requiring degrees of freedom beyond the Standard Model, can arise in asymptotically safe quantum gravity. We find a negative answer with far-reaching consequences: new degrees of freedom beyond gravity and the Standard Model are necessary to give neutrinos a mass in the asymptotic-safety paradigm. Second, we explore whether the type-I seesaw mechanism is viable and discover an upper bound on the seesaw scale. The bound depends on the mass of the visible neutrino. We find a numerical value of ${10}^{14}\mathrm{GeV}$ for this bound when neglecting neutrino mixing for a visible mass of ${10}^{-10}\mathrm{GeV}$. Conversely, for the most “natural” value of the seesaw scale in a quantum-gravity setting, which is the Planck scale, we predict an upper bound for the neutrino mass of the visible neutrino of approximately ${10}^{-15}\mathrm{GeV}$. Third, we explore whether neutrinos could also be pseudo-Dirac neutrinos in asymptotic safety and find that this possibility can be accommodated.

Axions, grand unification, and string theory are each compelling extensions of the Standard Model. We show that combining these frameworks imposes strong constraints on the QCD axion mass. Using perturbative unitarity arguments and explicit string compactifications—such as those from the Kreuzer-Skarke (KS) type IIB ensemble—we find that the axion mass is favored to lie within the range ${10}^{-11}\mathrm{eV}\lesssim m_a\lesssim {10}^{-8}\mathrm{eV}$. This range is directly relevant for near-future axion dark matter searches, including ABRACADABRA/DMRadio and CASPEr. We argue that grand unification and the absence of proton decay suggest a compactification volume that keeps the string scale above the unification scale ($\sim {10}^{16}\mathrm{GeV}$), which in turn limits how heavy the axion can be. The same requirements limit the KS axiverse to have at most $\sim 47$ axions. As an additional application of our methodology, we search for axions in the KS axiverse that could explain the recent Dark Energy Spectroscopic Instrument hints of evolving dark energy but find none with high enough decay constant ($f_a\gtrsim 2.5\times {10}^{17}\mathrm{GeV}$); we comment on why such high decay constants and low axion masses are difficult to obtain in string compactifications more broadly.

A classification of soft supersymmetry breaking deformation of general four dimensional $\mathcal{N}=2$ superconformal field theory (SCFT) is provided. Given the large class of newly discovered $\mathcal{N}=2$ SCFTs and their known properties such as the central charges and full information of BPS operators, it is possible to get a huge number of new $\mathcal{N}=1$ SCFTs and nonsupersymmetric CFTs. Many properties of these new $\mathcal{N}=1$ SCFTs such as central charges, chiral spectrum and a duality can be derived from known information of parent $\mathcal{N}=2$ SCFT.

Correlators at finite density and temperature encode important information about a physical system, such as transport and causality. For a massive gas of particles in the relaxation time approximation of kinetic theory, we provide complete analytic results for all first order transport coefficients, including thermoelectric coefficients. We demonstrate the first complete picture of the complex structure of the correlators as a function of mass, providing an interpretation in terms of the causal structure of light cones. We provide a simple criterion to extract the effective light cone velocity from the cut of the retarded correlator.

Gravitational waves offer a key insight into the viability of classes of gravitational theories beyond general relativity. The observational constraints on their speed of propagation can provide strong constraints on generalized classes of broader gravitational frameworks. In this work, we reconsider the general class of Gauss-Bonnet theories in the context of teleparallel gravity, where the background geometry is expressed through torsion. We perform tensor perturbations on a flat Friedmann–Lemaître–Robertson–Walker background, and derive the gravitational wave propagation equation. We find that gravitational waves propagate at the speed of light in these classes of theories. We also derive the distance-duality relationship for radiation propagating in the gravitational wave and electromagnetic domains.

We present a very detailed derivation of solutions describing hairy black holes within the gravity-coupled Weinberg-Salam theory, which were previously reported in Gervalle and Volkov [Black holes with electroweak hair, Phys. Rev. Lett. 133, 171402 (2024)]. These black holes support a strong magnetic field that polarizes the electroweak vacuum and creates a condensate of massive fields carrying superconducting currents along the black hole horizon. The currents, in turn, generate a “corona” of magnetic vortex segments attached to the horizon at both ends. The condensate and corona together constitute the black hole hair. The extremal solutions approach, in the far field, the magnetic Reissner-Nordström configuration, with a total mass that is lower than the total charge, $M<|Q|$, due to the negative Zeeman energy of the condensate. This makes the removal of the hair energetically unfavorable. The maximally hairy black holes exhibit masses comparable to terrestrial values, with approximately 11% of their total mass stored in the hair. Given that these solutions arise within a well-tested theoretical framework, they are likely to have physical relevance.

We reconstruct the nonlinear matter power spectrum $P(k)$ using a joint analysis of gravitational lensing of the cosmic microwave background (CMB) and lensing of galaxies. This reconstruction is motivated by the $S_8$ tension between early-universe CMB predictions and late-time observables. We use CMB lensing data from the Atacama Cosmology Telescope DR6 and cosmic shear data from the Dark Energy Survey (DES) Y3 release to perform a gravity-only (i.e., no baryonic feedback) fit to $P(k)$ in bins of wave number, within a model with a cosmological constant $\mathrm{\Lambda }$ and a cold dark matter component ($\mathrm{\Lambda }$CDM). We find that with DES cosmic shear data alone, $P(k)$ departs from the early-universe CMB prediction on all scales. The joint fit with CMB lensing is consistent on large scales $k<0.2{\mathrm{Mpc}}^{-1}$ but shows an $\sim 2\sigma$ deviation from scale independence when extending to $k=10h/\mathrm{Mpc}$. We compare our agnostic $P(k)$ reconstruction to baryonic feedback models and nonstandard dark matter models: Reasonable variations of both scenarios can recover the shape and amplitude of the suppression. We discuss the advances needed to disentangle these physical effects with a full mapping of $P(k,z)$.

By measuring, modeling and interpreting cosmological datasets, one can place strong constraints on models of the Universe. Central to this effort are summary statistics such as power spectra and bispectra, which condense the high-dimensional data into low-dimensional representations. In this work, we introduce a modern set of estimators for computing such statistics from three-dimensional clustering data, and provide a flexible python/cython implementation; polybin3d. Working in a maximum-likelihood formalism, we derive general estimators for the two- and three-point functions, which yield unbiased spectra regardless of the survey mask and weighting scheme. These can be directly compared to theory without the need for mask-convolution. Furthermore, we present a numerical scheme for computing the optimal (minimum-variance) estimators for a given survey, which is shown to reduce error-bars on large-scales. Our python package includes both general “unwindowed” estimators and their idealized equivalents (appropriate for simulations), each of which are efficiently implemented using fast Fourier transforms and Monte Carlo summation tricks, and additionally supports graphics processing unit acceleration using jax. These are extensively validated in this work, with Monte Carlo convergence (relevant for masked data) achieved using only a small number of iterations (typically $<10$ for bispectra). This will allow for fast and unified measurement of two- and three-point functions from current and upcoming survey data.

The W50 nebula around microquasar SS 433, powered by supercritical accretion, features two “extended jets” (tens of pc long and a few pc wide) from which polarized x-ray and very high-energy radiation above 100 TeV is detected. Here we present a model of very high-energy particle acceleration in these extended jets. In the “minimalist” model (discussed in Churazov, Khabibullin, and Bykov, 2024), a collimated outflow aligned with the rotation axis is propagating through a more isotropic wind produced by the accretion disk. The observed extended x-ray jets in this model are associated with the formation of strong recollimation magnetohydrodynamics shocks after the collision of the collimated outflow with the isotropic wind termination surface. The spectra of electrons and protons up to PeV energies are simulated with a nonlinear Monte Carlo model of diffusive shock acceleration with turbulent magnetic field amplification. The overall efficiency of the jets power transfer to accelerated protons in this model is above 10% and about 0.5% for electrons above 50 TeV. The magnetic field amplification by Bell’s instability due to the electric current of cosmic rays escaping the accelerator produces highly anisotropic magnetic turbulence in the shock downstream. This results in the polarized synchrotron x-ray emission with the photon electric vector predominantly transverse to the jet direction and the degree of polarization above 20%. The model is able to reproduce the observed spectra and intensity profiles of nonthermal x-ray and gamma-ray emission, which are both dominated by the leptonic radiation.

Young massive clusters and open clusters are widely considered as potential environments for assembling merging binary stellar-remnant black holes (BBH) via dynamical interactions. However, such moderate mass systems (typically, ${10}^3{M}_{\odot }-{10}^4{M}_{\odot }$) are susceptible to being disrupted by the external tidal field of their host galaxies, potentially limiting their effectiveness as gravitational-wave sources. In this study, I investigate the formation of BBH mergers in tidally dissolving star clusters. This is achieved with a newly computed grid consisting of 95 evolutionary model star clusters, where the clusters are subjected to a varying extent of tidal stripping. The cluster evolutions are computed with the direct $N$-body integrator nbody7 that includes, among others, treatments for post-Newtonian effects in compact-binary members, mass loss due to stellar evolution, formation of stellar remnants, and tidal stripping. It is found that even strong tidal stripping does not quench the formation of a black hole (BH) core inside a cluster or the formation of dynamical BBH mergers in the system. The overall properties of BBH mergers, e.g., the form of the distribution of merger delay time, primary mass, and mass ratio, and the redshift evolution of merger rate are not significantly altered by the extent of tidal stripping of the parent cluster population. Furthermore, even strongly tidally stripped clusters are capable of dynamically forming Gaia-BH-like detached BH–main-sequence-star binaries that escape into the galactic field. Limitations of the present study and potential future improvements are discussed.

We investigate nonradial $f$-mode oscillations of protoneutron stars in full general relativity, employing equations of state described by the Brueckner-Hartree-Fock theory or the relativistic mean field model, while assuming isentropy and fixed lepton fractions for the internal structure. The validity of various universal relations for cold neutron stars involving $f$-mode characteristics and macroscopic properties of the star is confirmed for those isentropic protoneutron stars (PNSs). Prospects of observations are also discussed. According to simulation results, we then model details of the thermal and trapping profiles in a PNS with the canonical mass. The corresponding $f$-mode frequencies and gravitational-wave strain amplitudes are presented. The validity of the universal relations during the evolution to the formation of a cold neutron star is confirmed.

We study the purely gravitational signatures of dark matter from the ultralight to the ultraheavy mass range in proposed long-baseline atom gradiometers, focusing on terrestrial designs, such as AION-km and MAGIS-km, as well as space-based concepts, such as MAGIS-space, AEDGE and $\mathrm{AEDGE}+$. Due to its exceptional acceleration sensitivity and depending on astrophysical backgrounds, a detector similar to $\mathrm{AEDGE}+$ could detect a dark matter subcomponent which constitutes $\mathcal{O}(10\%)$ of the local dark matter energy density and is populated by compact clumps of mass between ${10}^6\mathrm{kg}$ and ${10}^{10}\mathrm{kg}$ (${10}^{-25}{M}_{\odot }\lesssim M\lesssim {10}^{-21}{M}_{\odot }$) in an otherwise unexplored region of dark matter model space. Furthermore, because the gravitational observable depends on the relative gravitational time delay measured by spatially separated atomic clouds, we find that atom gradiometers are parametrically more sensitive than laser interferometers, such as LIGO and LISA, to fast-oscillating spacetime perturbations sourced by energy density and pressure fluctuations of ultralight dark matter. Depending on astrophysical backgrounds, a detector akin to $\mathrm{AEDGE}+$ could probe a DM overdensity of $\mathcal{O}(10)$ times the local dark matter energy density for masses $m\lesssim {10}^{-17}\mathrm{eV}$.

We demonstrate the cancellation of chiral anomalies in the Standard Model (SM) effective field theory (EFT), achieved through a consistent choice of loop momentum routing in triangle diagrams with dimension-6 operator insertions. By enforcing gauge invariance and Bose symmetry, we show that Goldstone-boson contributions cancel anomalies arising from massive gauge-boson vertices, thereby preserving the consistency of the SM EFT. We compute neutral triple gauge-boson vertices at one loop, revealing dominant contributions from dimension-6 operators at all energies below the EFT cutoff. A UV-complete anomaly-free model with a heavy vectorlike electron validates our approach, illustrating how heavy fermion decoupling generates SM EFT operators while maintaining anomaly cancellation. Our results highlight the phenomenological relevance of these vertices for probing new physics at colliders, particularly through dimension-6 effects that scale as the inverse of the center of mass energy squared, $1/s$, offering a viable pathway for experimental detection.