Based on our previous work, we study the harmonic coefficient of both inclusive and diffractive azimuthal angle dependent lepton-jet correlations in the Hadron-Electron Ring Accelerator and the future electron-ion collider. Numerical calculations for inclusive and diffractive harmonics, and the ratio of harmonics in $e+\mathrm{Au}$ and $e+p$, indicate their strong discriminating power for nonsaturation models and saturation models. Additionally, we demonstrate that the $t$-dependent diffractive harmonics can serve as novel observables for the nuclear density profile.

Resonance, bound-state, and virtual-state pole positions of the $f_0(500)$ scalar meson are computed as a continuous function of pion mass in the framework of a unitarized and analytic coupled-channel model for scalar mesons, described as dynamical quark-antiquark states. The $f_0(500)$ is modeled with both light and strange $q\overline{q}$ seeds, mixing with each other through the common $S$-wave $\pi \pi$, $K\overline{K}$, and $\eta \eta$ meson-meson decay channels. The few model parameters are fitted to experimental $S$-wave $\pi \pi$ phase shifts up to 1 GeV. In the case of the physical ${\pi }^{\pm }$ mass of 139.57 MeV, resonance poles at $(460-i222)\mathrm{MeV}$ and $(978-i37.2)\mathrm{MeV}$ are found for the $f_0(500)$ and $f_0(980)$, respectively. Resonance, bound-state, and virtual-state pole trajectories are computed and plotted as a function of pion masses up to 500 MeV, both in the complex-energy and complex-momentum planes. The results are discussed and compared to the most advanced lattice QCD computations employing interpolators that correspond to the $q\overline{q}$ and meson-meson channels in the present model, that is, for a few discrete values of the unphysical pion mass in those lattice calculations.

Higher-order QED radiative corrections to the muon decay spectrum are evaluated within the QED structure function approach in the next-to-leading-order logarithmic approximation. New analytical results are given in the $\mathcal{O}({\alpha }^3{\ln }^2(m_{\mu }^2/m_e^2))$ order. Earlier results in the $\mathcal{O}({\alpha }^2{\ln }^1(m_{\mu }^2/m_e^2))$ and $\mathcal{O}({\alpha }^3{\ln }^3(m_{\mu }^2/m_e^2))$ orders are partially corrected. Numerical estimates of different contributions are presented.

Precision measurements of antineutrino elastic scattering on hydrogen from future neutrino experiments offer a unique opportunity to access the low-energy structure of protons and neutrons. We discuss the determination of the nucleon axial-vector form factor and radius from antineutrino interactions on hydrogen that can be collected at the future Long-Baseline Neutrino Facility and study the sources of theoretical and experimental uncertainties. The projected accuracy would improve existing measurements by 1 order of magnitude and be competitive with contemporary lattice-QCD determinations, potentially helping to resolve the corresponding tension with measurements from (anti)neutrino elastic scattering on deuterium. We find that the current knowledge of the nucleon vector form factors could be one of the dominant sources of uncertainty. We also evaluate the constraints that can be simultaneously obtained on the absolute ${\overline{\nu }}_{\mu }$ flux normalization.

It is well known that the experience of a linearly accelerated observer with acceleration $a$, interacting with a massless scalar field in its vacuum state in $3+1$ Minkowski spacetime, is identical to that of a static observer interacting with a massless scalar field in a thermal state of temperature $a/2\pi$ in $3+1$ Minkowski spacetime. We study the robustness of this duality by comparing an observer undergoing circular motion in a thermal bath with an observer that undergoes circular motion around a linearly accelerated trajectory. We find that in most regimes, observers in these two cases experience the field in different ways, and are generally able to tell the difference between the two cases by measuring observables localized along their trajectories.

A neutron star in an inspiraling binary system is tidally deformed by its companion, and the effect leaves a measurable imprint on the emitted gravitational waves. While the tidal interaction falls within the regime of static tides during the early stages of inspiral, a regime of dynamical tides takes over in the later stages. The description of dynamical tides found in the literature makes integral use of a spectral representation of the tidal deformation, in which it is expressed as a sum over the star’s normal modes of vibration. This description is deeply rooted in Newtonian fluid mechanics and gravitation, and we point out that considerable obstacles manifest themselves in an extension to general relativity. To remedy this, we propose an alternative, modeless description of dynamical tides that can be formulated in both Newtonian and relativistic mechanics. Our description is based on a time-derivative expansion of the tidal dynamics, in which the external, orbital timescale associated with the tidal field is taken to be long compared with the internal, hydrodynamical timescale associated with the neutron star. The tidal deformation is characterized by two sets of Love numbers: the familiar static Love numbers $k_{\ell }$, which appear in the regime of static tides, and the dynamic Love numbers ${\ddot{k}}_{\ell }$, which emerge in the regime of dynamical tides. These numbers are computed here for polytropic stellar models in both Newtonian gravity and general relativity. On the face of it, the time-derivative expansion of the tidal dynamics seems to preclude any attempt to capture an approach to resonance, which occurs when the frequency of the tidal field becomes equal to a normal-mode frequency; such an approach is the main reason for which the regime of dynamical tides becomes important in the late inspiral, and it is fully captured by the mode representation of the tidal deformation. To overcome this limitation, we propose a pragmatic extension of the time-derivative expansion, which does capture an approach to resonance. We demonstrate that with this extension, our formulation of dynamical tides should be just as accurate as the $f$-mode truncation of the mode representation, in which the sum over modes is truncated to a single term involving the star’s fundamental mode of vibration.

We study transformations of the dynamical fields—a metric, a flat affine connection and a scalar field—in scalar-teleparallel gravity theories. The theories we study belong either to the general teleparallel setting, where no further condition besides vanishing curvature is imposed on the affine connection, or the symmetric or metric teleparallel gravity, where one also imposes vanishing torsion or nonmetricity, respectively. For each of these three settings, we find a general class of scalar-teleparallel action functionals which retain their form under the aforementioned field transformations. This is achieved by generalizing the constraint of vanishing torsion or nonmetricity to nonvanishing, but algebraically constrained torsion or nonmetricity. We find a number of invariant quantities which characterize these theories independently of the choice of field variables, and relate these invariants to analogues of the conformal frames known from scalar-curvature gravity. Using these invariants, we are able to identify a number of physically relevant subclasses of scalar-teleparallel theories. We also generalize our results to multiple scalar fields, and speculate on further extended theories with nonvanishing but algebraically constrained curvature.

The effectiveness of the hyperbolic relaxation method for solving the Einstein constraint equations numerically is studied here on a variety of compact orientable three-manifolds. Convergent numerical solutions are found using this method on manifolds admitting negative Ricci scalar curvature metrics, i.e., those from the $H^3$ and the $H^2\times S^1$ geometrization classes. The method fails to produce solutions, however, on all the manifolds examined here admitting non-negative Ricci scalar curvatures, i.e., those from the $S^3$, $S^2\times S^1$, and the $E^3$ classes. This study also finds that the accuracy of the convergent solutions produced by hyperbolic relaxation can be increased significantly by performing fairly low-cost standard elliptic solves using the hyperbolic relaxation solutions as initial guesses.

The hyperbolic encounters of two massive objects are characterized by the emission of a gravitational wave burst, with most of the energy released during the closest approach (near the periastron). The detection of such events, different from the well-known inspiral emission, would be an interesting discovery and provide complementary information to observations of binary mergers of black holes and neutron stars in the observable Universe, shedding light, for instance, on the clustering properties of black holes and providing valuable hints on their formation scenario. Here, we analyze the dynamics of such phenomena in the simplest case where two compact objects follow unbound/hyperbolic orbits. Moreover, we explore the effects of orbital precession on the gravitational wave emission, since the precession encodes certain general relativistic effects between two bodies. We also provide templates for the strain of gravitational waves and the power spectrum for the emission, and analytical expressions for the memory effect associated with such signals.

It is well known that there are several long-standing problems implying the discordance of the $\mathrm{\Lambda }\mathrm{CDM}$ model. Although most of the models proposed to resolve these problems assume that dark matter is pressureless, it is still possible that dark matter is not cold, as current observations have not ruled out this possibility yet. Therefore, in this article, we treat the dark matter equation of state parameter as a free parameter, and apply observational data to investigate the noncoldness of dark matter. Impressing by the simplicity of the phenomenological emergent dark energy (PEDE) and its ability to relieve the Hubble tension, we propose the $\mathrm{PEDE}+w_{\mathrm{dm}}$ model based on PEDE and noncold dark matter. We then place constraints on this model in light of the Planck 2018 cosmic microwave background (CMB) anisotropies, baryon acoustic oscillation (BAO) measurements, and the Pantheon compilation of type Ia supernovae. The results indicate a preference for a negative dark matter equation of state parameter at 95% CL for all datasets except CMB alone and $\mathrm{CMB}+\mathrm{BAO}$, which suggests that the noncoldness assumption of dark matter is worth investigating further in order to understand the nature of dark matter. The Hubble tension is alleviated in this scenario compared to the $\mathrm{\Lambda }\mathrm{CDM}$ model, with a significance below $3\sigma$ level for all datasets except $\mathrm{CMB}+\mathrm{Pantheon}$. However, from the analysis based on Bayesian evidence, we clearly see that the datasets favor $\mathrm{\Lambda }\mathrm{CDM}$ over the $\mathrm{PEDE}+w_{\mathrm{dm}}$ model.

We explore how dynamical friction in an ultralight dark matter (ULDM) background is affected by dark matter self-interactions. We calculate the force of dynamical friction on a point mass moving through a uniform ULDM background with self-interactions, finding that the force of dynamical friction vanishes for sufficiently strong repulsive self-interactions. Using the pseudospectral solver ultradark.jl, we show with simulations that reasonable values of the ULDM self-interaction strength and particle mass cause $\mathcal{O}(1)$ differences in the acceleration of an object like a supermassive black hole (SMBH) traveling near the center of a soliton, relative to the case with no self-interactions. For example, repulsive self-interactions with $\lambda ={10}^{-90}$ yield a deceleration due to dynamical friction $\approx 70\%$ smaller than a model with no self-interactions. We discuss the observational implications of our results for SMBHs near soliton centers and for massive satellite galaxies falling into ultralight axion halos and show that outcomes are dependent on whether a self-interaction is present or not.

Cosmic ray (CR) spectra show a two-component structure for both primary and secondary particles. In our study, we think that this feature roots in a nearby source halo. This halo acts as a reservoir for CRs in the source region, leading to the high-energy component. Furthermore, it acts as a barrier, effectively halting the travel of CRs from other sources directly in the disk, this causes CRs to propagate from the outer disk and contribute to the low-energy component. As a result, all the spectra anomalies could be well reproduced. This scenario can be extended to the whole disk, we prospect high-energy diffuse $\gamma$-ray emissions exhibit highly spatial dependence, emanating from local sources. We urge HAWC/LHAASO to detect diffuse $\gamma$ ray on the spatial scale of a few square degrees.

TianQin is a proposed mission for space-based gravitational-wave detection that features a triangular constellation in circular high Earth orbits. The mission entails three drag-free controlled satellites and long-range laser interferometry with stringent beam pointing requirements at remote satellites. For the payload architecture and pointing control strategies, having two test masses per satellite, one for each laser arm, and rotating entire optomechanical assemblies (each consisting of a telescope, an optical bench, an inertial sensor, etc.) for constellation breathing angle compensation represent an important option for TianQin. In this paper, we examine its applicability from the perspectives of test mass and satellite control in the science mode, taking into account of perturbed orbits and orbital gravity gradients. First, based on the orbit-attitude coupling relationship, the required electrostatic forces and torques for the test mass suspension control are estimated and found to be sufficiently small for the acceleration noise budget. Further optimization favors configuring the centers of masses of the two test masses collinear and equidistant with the center of mass of the satellite, and slightly offsetting the assembly pivots from the electrode housing centers forward along the sensitive axes. Second, the required control forces and torques on the satellites are calculated, and thrust allocation solutions are found under the constraint of having a flat-top sunshield on the satellite with varying solar angles. The findings give a green light to adopting the two test masses and telescope pointing scheme for TianQin.

Opportunities for searches for axionlike particles (ALPs) coupling to photons in $e^{+}{e}^{-}$ collisions at the Future Circular Collider (FCC-ee) and International Linear Collider (ILC) are investigated. We perform a study of the photon-fusion production of ALPs decaying into two photons, $e^{+}{e}^{-}\stackrel{\gamma \gamma }{\to }{e}^{+}a(\gamma \gamma )e^{-}$, over the light-by-light continuum background, for the planned FCC-ee and ILC center-of-mass energies and integrated luminosities. An analysis of the feasibility measurements is presented using parametrized simulations for two types of detectors. Upper limits at 95% confidence level (C.L.) on the cross section for ALP production, $\sigma (\gamma \gamma \to a\to \gamma \gamma )$, and on the ALP-photon coupling are obtained over the $m_a\approx 0.1–1000\mathrm{GeV}$ ALP mass range, and compared to current and future collider searches. Production cross sections down to $\sigma (\gamma \gamma \to a\to \gamma \gamma )\approx 1\mathrm{fb}$ (1 ab) will be probed at $m_a\approx 1$ (300) GeV, corresponding to constraints on the axion-photon coupling as low as $g_{\mathrm{a}\gamma \gamma }\approx 2\times {10}^{-3}{\mathrm{TeV}}^{-1}$.

Left-right symmetric models (LRSM) were proposed to reconcile the apparent parity violation in weak interactions with our intrinsic notion of fundamental parity symmetry. It was quickly realized that LRSM offers a viable framework for explaining neutrino masses by incorporating right-handed neutrinos, $N$, into its spectrum. In this study, we investigate for the first time the potential of future lepton colliders (including the FCC-ee, CEPC, ILC, CLIC, and a muon collider) to detect signals stemming from $N$’s, focusing primarily on displaced vertex signals, and on prompt signals to a lesser degree. Our results demonstrate that these signals can effectively probe the characteristic scales of LRSM, providing evidence that would be unobtainable through any other experimental means.

This work presents a model for testing Lorentz and $CPT$ symmetry through sidereal-variation studies of the hyperfine-Zeeman deuterium ground-state transition frequencies. It represents an advancement over previous models by using a well-established deuteron wave function parametrization to calculate contributions from nucleon Lorentz-violating operators toward the Lorentz-violating frequency shift. Furthermore, this work extends the analysis beyond the zeroth-boost order previously considered. This study centers on deuterium’s potential for testing Lorentz-violating nonminimal terms. Specifically, it compares the prospects of an ongoing deuterium experiment with the current best limits on nonminimal coefficients. The conclusion drawn is that the deuterium experiment holds the potential to enhance and establish first-time limits on nonminimal proton, neutron, and electron SME coefficients, marking it as a valuable experiment in the current worldwide systematic search for Lorentz and $CPT$ violation.

The $N^{*}(1535)$ can be dynamically generated in the chiral unitary approach with the coupled channels, $K^0{\mathrm{\Sigma }}^{+},K^{+}{\mathrm{\Sigma }}^0,K^{+}\mathrm{\Lambda }$, and $\eta p$. In this work, we evaluate the correlation functions for every channel and face the inverse problem. Assuming the correlation functions to correspond to real measurements, we conduct a fit to the data within a general framework in order to extract the information contained in these correlation functions. The bootstrap method is used to determine the uncertainties of the different observables, and we find that, assuming errors of the same order than in present measurements of correlation functions, one can determine the scattering length and effective range of all channels with a very good accuracy. Most remarkable is the fact that the method predicts the existence of a bound state of isospin $\frac{1}{2}$ nature around the mass of the $N^{*}(1535)$ with an accuracy of 6 MeV. These results should encourage the actual measurement of these correlation functions (only the $K^{+}\mathrm{\Lambda }$ one is measured so far), which can shed valuable light on the relationship of the $N^{*}(1535)$ state to these coupled channels, a subject of continuous debate.

We determine color-octet nonrelativistic QCD matrix elements for quarkonium decays from moments of the two-point correlation function of the QCD field-strength tensor computed in the refined Gribov-Zwanziger theory. We find that a tree-level calculation in the refined Gribov-Zwanziger theory can give a suitable description of the QCD field-strength correlation function at both short and long distances, which leads to moments that are infrared finite and can be properly renormalized. By using the color-octet matrix elements we obtain, we quantitatively improve the nonrelativistic effective field theory description of quarkonium decay rates, especially for the ${\chi }_{QJ}$ and ${\eta }_Q$ states, where $Q=c$ or $b$.

We study (near-)circular orbits of charged particles in the background of charged black holes in asymptotically anti–de Sitter (AdS) spacetimes of arbitrary dimensionality. We calculate the energy and angular momentum of such particles in a large-radius limit. This allows us to compute the anomalous dimension of the dual charged double-twist operators in a large-spin expansion, making a prediction for the bootstrap analysis at large charge and spin. We relate our result to the weak gravity conjecture (WGC) for AdS black holes of all sizes. We also discuss the relation of WGC with the existence of the innermost stable circular orbit (ISCO) in any dimension.

Black hole solutions of general relativity exhibit a symmetry for the static perturbations around these spacetimes, known as “ladder symmetry.” This symmetry proves useful in constructing a tower of solutions for perturbations and elucidating their general properties. Specifically, the presence of this symmetry leads to the vanishing of the tidal Love number associated with black holes. In this work, we find the most general spherical, symmetric, and static black hole spacetime that accommodates this ladder symmetry for scalar perturbation. Furthermore, we extend our calculations beyond spherical symmetry to find the class of stationary Konoplya-Rezzolla-Zhidenko black holes, which also possess a similar ladder structure.