It was recently shown that the time variation of the polarization of electromagnetic waves from pulsars can be used, in cross-correlation with pulsar timing, to probe the chirality of an isotropic gravitational wave background. Here, we show that the expression for the cross-correlation is derived efficiently with the total-angular-momentum formalism and use this framework to extend the formulation to cross-correlation with astrometry. We do so for spin-1 gravitational waves (that may arise in alternative-gravity theories) as well as the general-relativistic spin-2 gravitational waves.

Parton distribution functions (PDFs) describe the inner, nonperturbative structure of hadrons. Their computation involves matrix elements with a Wilson line along a direction on the light cone, posing significant challenges in Euclidean lattice calculations, where the time direction is not directly accessible. We propose implementing the light-front Wilson line within the Hamiltonian formalism using tensor network techniques. The approach is demonstrated in the massive Schwinger model (quantum electrodynamics in $1+1$ dimensions), a toy model that shares key features with quantum chromodynamics. We present accurate continuum results for the fermion PDF of the vector meson at varying fermion masses, obtained from first-principle calculations directly in Minkowski space. Our strategy also provides a useful path for quantum simulations and quantum computing.

We extend a top-down holographic model of a Weyl semimetal to finite charge density and compute the fermionic spectral function by introducing two probe fermions of opposite chirality. The model is controlled by the boundary fermion mass $M$ and the chemical potential $\mu$. In the zero density, small-$M$ limit, we recover four energy bands, two Weyl points, and linear dispersion in their vicinity, the hallmarks of a Weyl semimetal. As $M$ increases, the bands between the Weyl points become progressively compressed and the spectral weight associated with those bands is smeared out. At finite charge density, we map the Fermi surface in momentum space and identify a Lifshitz transition: two distinct Fermi pockets, each enclosing a different Weyl point, merge into a single large Fermi surface that encloses both. This transition can be induced by either control parameter. Varying $M$ alters the band structure and thus the band shape, which drives the Lifshitz transition, whereas changing $\mu$ shifts the bands relative to the Fermi level without qualitatively changing the band structure, producing the Lifshitz transition by moving the band positions.

We investigate the role of framing in a family of $1/24$ Bogomol’nyi–Prasad–Sommerfield (BPS) Wilson loops in Aharony-Bergman-Jafferis-(Maldacena) theory, which define flows between $1/6$ BPS and the $1/2$ BPS superconformal fixed points. We analyze in perturbation theory how framing affects both the expectation values of these operators and the correlation functions of local insertions on the defect, as well as its interplay with renormalization group flow and the $g$-theorem. We obtain a nontrivial identity between the one-point function of the defect stress tensor and a $\mathcal{Q}$-exact correlator, which establishes a direct link between scale, superconformal invariance, cohomological equivalence and framing. This analysis confirms that framing one preserves supersymmetry and cohomological equivalence of operators at the quantum level, establishing a precise match with localization predictions. Finally, we propose a holographic interpretation of framing at strong coupling, identifying it with a coupling to the background $B$-field in the dual string theory.

Compatibility with T-duality severely constrains higher-derivative corrections to the low-energy supergravity limits of string theory. For example, it suggests that Lorentz transformations for heterotic strings are modified in precisely the way required for the Green-Schwarz anomaly cancellation mechanism. A systematic procedure to construct the resulting generalized Green-Schwarz transformations is the generalized Bergshoeff-de Roo identification (gBdRi) J. High Energy Phys. 11 (2018) 160; J. High Energy Phys. 01 (2021) 171. Although it in principle allows computing ${\alpha }^{\prime }$-corrections to higher and higher orders, technically it becomes unfeasible beyond ${\alpha }^{\prime 2}$. We revisit this problem with an alternative approach to the gBdRi, which we have recently developed. It gives rise to a very simple all-order transformation law whose closure we verify by explicitly computing the resulting gauge algebra.

The nonlinearly coupled Einstein-matter field equations predict the existence of shadows with well-defined boundaries around black holes. We prove that, in spherically symmetric hairy black-hole spacetimes whose matter fields satisfy the weak energy condition, the radii of these shadows are bounded from below by the dimensionless relation $r_{\mathrm{sh}}/r_{\mathrm{H}}\ge 3\sqrt{3}/2$, where $r_{\mathrm{H}}$ is the horizon radius of the central hairy black hole. The characteristic shadow of the (bald) Schwarzschild black-hole spacetime saturates the analytically derived lower bound.

Scalar fields of masses between ${10}^{-21}$ and ${10}^{-11}\mathrm{eV}/c^2$ can exhibit enhanced gravitational interactions with black holes and form scalar clouds around them. Such a cloud modifies the dynamics of a coalescing black hole binary, and the resulting gravitational waves may provide a new channel to detect light scalar fields, such as axionlike particles or wavelike dark matter candidates. In this work, we simulate a series of black hole mergers with mass ratios $q=1$ and $q=1/2$, immersed in a scalar field overdensity with masses in the range $M{\mu }_{\mathrm{S}}\in [0,1.0]$. To do so, we implemented a constraint-satisfying initial data solver based on the puncture method, we improved the accuracy of our open-source software canuda to eighth order finite differences, and we reduced the initial orbital eccentricity. We investigate the impact of the scalar mass on the gravitational and scalar radiation. We find that binaries can undergo a delayed or an accelerated merger with respect to vacuum. Our study highlights the challenge and importance of accurately modeling black hole binaries in dark matter environments.

We investigate the threshold of collapse of a massless complex scalar field in axisymmetric spacetimes under the ansatz of Choptuik et al. [Phys. Rev. Lett. 93, 131101 (2004)], in which a symmetry depending on the azimuthal parameter $m$ is imposed on the scalar field. This allows for both nonvanishing twist and angular momentum. We extend earlier work to include higher angular modes. Using the pseudospectral code bamps with a new adapted symmetry reduction method, which we call $m$ cartoon, and a generalized twist-compatible apparent horizon finder, we evolve near-critical initial data to the verge of black hole formation for the lowest nontrivial modes, $m=1$ and $m=2$. For $m=1$ we recover discrete self-similarity with echoing period $\mathrm{\Delta }\simeq 0.42$ and power-law scaling with exponent $\gamma \simeq 0.11$, consistent with earlier work. For $m=2$ we find that universality is maintained within this nonzero fixed-$m$ symmetry class but with smaller period and critical exponents, $\mathrm{\Delta }\simeq 0.09$ and $\gamma \simeq 0.035$, establishing an explicit dependence of the critical solution on the angular mode. Analysis of the relation between the angular momentum and the mass of apparent horizons at the instant of formation, $J_{\mathrm{AH}}-M_{\mathrm{AH}}$, shows that the effect of angular momentum is minimal at the threshold, with ${\chi }_{\mathrm{AH}}=J_{\mathrm{AH}}/M_{\mathrm{AH}}^2\to 0$, and, therefore, excludes extremal black holes for the families under consideration. This conclusion is further validated by the negative subdominant Lyapunov exponent ${\lambda }_1$, related to rotations, implying the angular momentum scales down faster than the mass as the threshold is approached. In the presence of angular momentum, $m>0$, we observe a single center of collapse, with quantitative evidence from curvature invariants indicating no competition between the scalar and vacuum thresholds, in contrast to what we witnessed in the absence of twist [K. Marouda, D. Cors, H. R. Rüter, F. Atteneder, and D. Hilditch, [Phys. Rev. D 109, 124042 (2024)] ]. Our results demonstrate that while universality and discrete self-similarity hold within each $m$ sector, the critical universal values vary with $m$, and neither extremality nor bifurcation occur in the complex scalar field model within the families considered here.

Extreme mass-ratio inspirals (EMRIs) are one of the key sources of gravitational waves for space-based detectors such as the Laser Interferometer Space Antenna. However, their detection remains a major data analysis challenge due to the signals’ complexity and length. We present a semicoherent, time-frequency search strategy for detecting EMRI harmonics without relying on full waveform templates. We perform an injection and search campaign of single mildly eccentric equatorial EMRIs in stationary Gaussian noise. The detection statistic is constructed solely from the EMRI frequency evolution, which is modeled phenomenologically using a singular value decomposition basis. The pipeline and the detection statistic are implemented in time frequency, enabling efficient searches over one year of data in approximately one hour on a single graphic processing unit. The search pipeline achieves 94% detection probability at $\mathrm{SNR}=30$ for a false-alarm probability of ${10}^{-2}$, recovering the frequency evolution of the dominant harmonic within 1% relative error. By mapping the EMRI parameters consistent with the recovered frequency evolution, we show that the semicoherent detection statistic enables a subpercent precision estimation of the EMRI intrinsic parameters. These results establish a computationally efficient framework for constructing EMRI proposals for the LISA global fit.

We investigate the connection between thermodynamic phase transitions and quasinormal modes (QNMs) in charged black holes with a positive curvature constant, within the framework of $F(R)$-Euler-Heisenberg gravity. Nonlinear electromagnetic fields lead to rich thermodynamic phase structures and significantly affect the QNMs of massless scalar fields. By analyzing the QNM spectrum, we find that the transition point marking the disappearance of the divergence in the QNM slope parameter $K$ aligns with the change of the thermodynamic phase structure described by the heat capacity, within the bounds of computational uncertainty. This precise matching holds under variations of the curvature parameter and charge. Furthermore, we show that a larger angular quantum number $l$ diminishes this correspondence, while a higher overtone number $n$ restores it beyond a threshold. These findings demonstrate that thermodynamic phase transitions of black holes carry embedded dynamical information, uncovering a fundamental link between black hole thermodynamic and dynamical properties.

Primordial magnetic fields (PMFs) are magnetic fields generated during the early Universe. These fields are thought to be the seeds of extragalactic magnetic fields. The origin of PMFs is not well known. Further, if they are indeed sources of extragalactic fields, then there is a possibility that observations of extragalactic magnetic fields could provide insights into the primordial physics. With this motivation, we study the generation of the primordial magnetic field in the context of loop quantum cosmology (LQC). In LQC, inflation is preceded by a quantum bounce. In this work, we consider an electromagnetic field coupled to the background as a test field and study its evolution through the bounce and through the subsequent inflationary phase. We investigate the power spectra generated in LQC and show that it is scale-dependent. We study the power spectra with different initial conditions, discuss equivalent forms of coupling functions, investigate backreaction, and compute the amount of primordial magnetic field which can be measured today. We conclude the article with a summary and discussion of the results.

The oscillation feature in primordial power spectrum (PPS), a fingerprint of not only a wide class of models of inflation but new physics, is of significant theoretical interest, and can be imprinted on the cosmic microwave background (CMB). In this work, we present constraints on periodic oscillations in the PPS using the latest ACT DR6 and SPT-3G D1 CMB data with the precise measurements at high multipoles beyond the Planck angular resolution and sensitivity. It is found that the combination of SPT and ACT with Planck CMB dataset significantly tightens the upper bound to $A_{\log ,\mathrm{lin}}\lesssim 0.029$ at 95% CL, showing no hint for primordial oscillations, where $A_{\log ,\mathrm{lin}}$ are the amplitudes of logarithmic and linear oscillation in the PPS, respectively. Our work presents state-of-the-art CMB constraints on primordial oscillations, highlighting the power of the ground-based CMB experiments in constraining physics beyond the simplest slow-roll models.

The stochastic gravitational wave background (SGWB), arising from the incoherent superposition of numerous compact binary coalescences, serves as a powerful probe of both astrophysical populations and fundamental physics. In this work, we investigate the influence of gravitational lensing on the SGWB, focusing on primordial black holes (PBHs) as potential lenses. Assuming PBHs to be dark matter candidates with a broad cosmic distribution, we show that their lensing optical depth can be significantly enhanced, producing pronounced effects with relative deviations at the ${10}^{-1}$ level. By systematically varying the PBH mass $M_{\mathrm{PBH}}$ and abundance $f_{\mathrm{PBH}}$, we demonstrate that the mass predominantly determines the frequency-dependent diffraction features of the spectrum, while the abundance primarily amplifies the overall lensing-induced deviation. Although the SGWB from binary black holes has yet to be observed, our analytical results provide theoretical insight into the possible imprint of lensing on its spectrum and suggest that future detections could offer a novel avenue to constrain dark matter scenarios.

We present numerical simulations of dark matter and stellar dynamics in ultralight dark matter halos tailored to mimic dwarf galaxies. An important effect we observe is the dynamical evolution of the stellar half-light radius and velocity dispersion, which makes previous equilibrium models significantly incomplete. Based on half-light radius dynamical evolution, as well as velocity peaks due to soliton core condensation, we show that data from the Fornax, Carina, and Leo II dwarf galaxies disfavors particle masses in the range $5\times {10}^{-22}\mathrm{eV}\lesssim m\lesssim 5\times {10}^{-21}\mathrm{eV}$. Smaller boson masses, around $m\approx 1\times {10}^{-22}\mathrm{eV}$, could cause strong dynamical heating, but we caution that tidal stripping by the Milky Way could moderate the effect. A caveat in our analysis is the omission of stellar self-gravity, which could affect extrapolation back in time if the stellar body was much more compact in the past.

The flux of astrophysical neutrinos is now measured with unprecedented accuracy and over several decades of energy spectrum. Their origin traces back to hadronic collisions between protons and nuclei in the cosmic rays with hydrogen and helium in the target gas. To accurately interpret the data, a precise determination of the underlying cross sections is therefore mandatory. We present a new evaluation of the neutrino production cross section from $p+p$ collisions, building on our previous analysis of the production cross section for ${\pi }^{\pm }$, $K^{\pm }$, and minor baryonic and mesonic channels. Cross sections for scatterings involving nuclei heavier than protons are also derived. The novelty of our approach is the analytical description of the Lorentz-invariant cross section ${\sigma }_{\mathrm{inv}}$ and the fit of the model to the available accelerator data. We work with neutrino energies from 10 to ${10}^7\mathrm{GeV}$ and, correspondingly, to incident proton (nuclei) energies from 10 to ${10}^9\mathrm{GeV}$ (GeV/n). We obtain the total differential cross section $d\sigma (p+p\to \nu +X)/d{E}_{\nu }$ as a function of neutrino and proton energies, with an estimated uncertainty of 5% for neutrino energies below 100 GeV, increasing to 10% above TeV energies. Predictions are given for ${\nu }_e,{\nu }_{\mu },\overline{{\nu }_e}$, and $\overline{{\nu }_{\mu }}$. A comparison with state-of-the-art cross sections, all relying on Monte Carlo generators, is also presented. To facilitate the use by the community, we provide numerical tables and a script for accessing our energy-differential cross sections.

The minimal $R$-symmetric supersymmetric Standard Model with a seesaw mechanism extends the minimal $R$-symmetric supersymmetric Standard Model by incorporating right-handed neutrinos to generate neutrino masses via the type-I seesaw mechanism. This work presents a detailed analysis of lepton-flavor-violating (LFV) processes, including ${\ell }_i\to {\ell }_j\gamma$, ${\ell }_i\to 3{\ell }_j$, and Higgs decays $h\to {\ell }_i{\ell }_j$. Based on the current experimental limitations, we carry out detailed parameter scanning and numerical calculations to analyze the effects of different sensitive parameters on LFV. The numerical results show that the nondiagonal elements involving the initial and final leptons are the main sensitive parameters and LFV sources.

The existence of cosmic fields made from yet unknown light bosons is predicted in many extensions to the Standard Model. They are especially of interest as possible constituents of dark matter. To detect such light and weakly interacting fields, atomic precision measurements offer one of the most sensitive platforms. In this work, we derive which atomic observables are sensitive to what kind of cosmic field couplings. For this we consider fields that couple either through scalar, pseudoscalar, vector, axial vector, or tensor couplings. We derive the corresponding nonrelativistic atomic potentials. Based on their symmetry properties, these can induce direct energy shifts or induce atomic electric dipole, magnetic dipole, electric quadrupole as well as nuclear Schiff and anapole moments.

The Standard Model effective field theory (SMEFT) is constrained by current LHC data. Supposedly, extensions of the Standard Model involving heavy particles can be constrained by matching onto the SMEFT. However, the reliability of these indirect constraints compared to those derived directly from the UV model remains an open question. In this paper, we investigate whether four-quark operators can accurately capture the effects of an $R$-parity-violating (RPV) supersymmetric model on the production of pairs of top quarks, for parameters that satisfy all known constraints and lead to measurable effects. We assume that the sbottom is the lightest supersymmetric particle and focus on its interaction with a light quark and a top quark; the sbottom thus acts like a specific diquark. The four-quark operators arise by integrating out the sbottom at tree level. We analyze measurements of inclusive top-pair production by the CMS and ATLAS Collaborations. We find that the four-quark operators can accurately describe the RPV model’s effects only for very heavy sbottom squarks, where the effects are well below the sensitivity of LHC experiments for all values of the RPV coupling that satisfy unitarity constraints. Therefore present or near-future bounds on this RPV model cannot be derived from SMEFT analyses.

We perform a global Bayesian analysis of diffractive $\mathrm{J}/\psi$ production in $\gamma +p$ and $\gamma +\mathrm{Pb}$ collisions using a color glass condensate (CGC) based calculation framework. As past calculations have shown that CGC-based models typically overpredict the $\mathrm{J}/\psi$ production in $\gamma +\mathrm{Pb}$ collisions at high center of mass energy, we address the question of whether it is possible to describe coherent and incoherent diffractive $\mathrm{J}/\psi$ data from $\gamma +p$ collisions at Hadron–Electron Ring Accelerator (HERA) and the LHC, and from $\gamma +\mathrm{Pb}$ collisions at the LHC simultaneously. Our results indicate that a simultaneous description of $\gamma +p$ and $\gamma +\mathrm{Pb}$ data is challenging, with results improving when an overall $K$-factor—scaling $\gamma +p$ and $\gamma +\mathrm{Pb}$ cross sections to absorb model uncertainties—is introduced.

We examine the spectrum of the $\mathrm{\Sigma }({\frac{1}{2}}^{-})$ family based on the experimental $K^{-}p$ scattering data and lattice QCD simulations within the Hamiltonian effective field theory. Especially, two different scenarios are constructed in order to clarify whether there is one or two $\mathrm{\Sigma }({\frac{1}{2}}^{-})$ resonances with masses around 1.5–1.7 GeV. The relevant lattice QCD data support our scenario with two resonance poles at $1687-110i$ and $1714-14i\mathrm{MeV}$ in which the bare strange triquark core plays an important role. We also show an extra clear cusp structure around 1.4 GeV in our scattering T matrices associated with the odd-parity strange baryons.