We investigate the impact of the new measurement of the antineutrino-proton scattering cross section from the MINERvA Collaboration on generalized parton distributions (GPDs), particularly the polarized GPDs denoted as ${\tilde{H}}^q$. To achieve this, we perform some QCD analyses of the MINERvA data, in addition to all available data of the proton’s axial form factors. We demonstrate that MINERvA data lead to consistent results with other related experimental data, confirming the universality of GPDs. Our results indicate that MINERvA data can impose new constraints on GPDs, particularly on ${\tilde{H}}^q$. Our predictions for the proton’s axial charge radius, WACS cross section, and axial form factor show good consistency with those of other studies and measurements. This leads us to conclude that the result of a more comprehensive analysis, considering all related experimental data, is not only reasonable but also more reliable, even in light of existing tensions among the data. The present study can be considered as a guideline for performing a new and comprehensive QCD global analysis of GPDs including the MINERvA measurements like that presented in Hashamipour et al. [Generalized parton distributions at zero skewness, Phys. Rev. D 107, 096005 (2023).].

We compute for the first time the next-to-leading-order QCD corrections to the ${\overline{B}}_{(s)}\to D_{(s)}^{(*)}$ form factors at large hadronic recoil. Both the charm-quark-mass- and the strange-quark-mass- dependent pieces can generate the leading-power contributions to these form factors. Including further various power-suppressed contributions, we perform the combined fits of the considered form factors to both our large-recoil theory predictions and the lattice QCD results, thus improving upon the previous determinations of the lepton-flavor-universality ratios $\mathcal{R}(D^{(*)})$ significantly.

In the presence of boundaries, the quantum anomalies acquire additional boundary terms. In odd dimensions, the integrated conformal anomaly, for which the bulk contribution is known to be absent, is nontrivial due to the boundary terms. These terms became a subject of active study in the recent years. In the present paper, we continue our previous study [1,2] and compute explicitly the anomaly for fermions in dimensions $d=3$, 4 and 5. The calculation in dimension 5 is new. It contains both contributions of the gravitational field and the gauge fields to the anomaly. In dimensions $d=3$ and 4, we reproduce and clarify the derivation of the results available in the literature. Imposing the conformal invariant mixed boundary conditions for fermions in odd dimension $d$, we particularly pay attention to the necessity of choosing the doubling representation for gamma matrices. In this representation, there exists a possibility to define chirality and thus address the question of the chiral anomaly. The anomaly is entirely due to terms defined on the boundary. They are calculated in the present paper in dimensions $d=3$ and 5 due to both gravitational and gauge fields. To complete the picture, we reevaluate the chiral anomaly in $d=4$ dimensions and find a new boundary term that is supplementary to the well-known Pontryagin term.

The light propagation in plasma medium around stationary gravitating objects is studied in the geometrical optics limit. Static metrics with quadrupole moments are considered; however, most of our attention is on the stationary Hartle-Thorne metric and Kerr metric. Their different effects on the light deflection are compared. The deflection angle is given in a general analytic form, and the detailed calculations are performed in the weak-field limits and illustrated graphically. The trajectories of the light rays are constructed and compared, emphasizing the role of the quadrupole moment.

We analyze the impact of positivity conditions on static spherically symmetric deformations of the Schwarzschild space-time. The metric is taken to satisfy, at least asymptotically, the Einstein equation in the presence of a nontrivial stress-energy tensor, on which we impose various physicality conditions. We systematically study and compare the impact of these conditions on the space-time deformations. The universal nature of our findings applies to both classical and quantum metric deformations with and without event horizons. We further discuss minimal realizations of the asymptotic stress energy tensor in terms of physical fields. Finally, we illustrate our results by discussing concrete models of quantum black holes.

In this paper, utilizing the generalized off shell Helmholtz free energy, we explore the topological numbers of the four-dimensional static accelerating black hole and its AdS extension, as well as the static charged accelerating black hole and its AdS extension. Our analysis reveals a profound and significant impact of the acceleration parameter on the topological numbers associated with the static black holes; and different values (nonzero) of the acceleration parameter do not affect the topological numbers of the corresponding four-dimensional static accelerating black holes. In addition, we demonstrate that the electric charge parameter has an important effect on the topological number of the static neutral accelerating black holes, and the cosmological constant has a remarkable influence on the topological number of the static accelerating black hole. Furthermore, it is interesting to observe that the difference between the topological number of the asymptotically flat static accelerating black hole and that of its corresponding asymptotically flat static nonaccelerating black hole is always unity, and the difference between the topological number of the asymptotically AdS static accelerating black hole and that of its corresponding asymptotically AdS static nonaccelerating black hole is always $-1$. This new observation leads us to conjure that it might be valid also for other accelerating black holes. Of course, this captivating conjecture requires empirical verification through comprehensive investigation into the topological numbers of other accelerating black holes and their corresponding usual counterparts.

The “${\varphi }^2$” slow roll inflation combined with general relativity is largely excluded by Planck data. In this paper, we consider the same potential combined with the $R+C^2$ gravity of purely virtual particles (or fakeons), where the would-be ghost introduced by the Weyl tensor term, $C^2$, is quantized with the fakeon prescription. We compute the tensor power spectrum in the full theory by means of the cosmic renormalization group formalism and critically examine its physical meaning. In particular, we show that it is not possible to retrieve the power spectrum of the fakeon free-theory by considering the decoupling limit of the purely virtual particles. We provide a physical explanation in terms of the causal structure of the theory to infer that a model of quadratic inflation from purely virtual particles is also discarded from a phenomenological point of view.

We study a scattering problem of gravitational waves (GWs) by an axion domain wall in Chern-Simons (CS) gravity. We find that a circular polarization of GWs is produced after passing through the domain wall. It turns out that the circular polarization is sizable if the frequency of the GW is comparable to a critical value determined by the characteristic CS length scale and the energy scale of the axion domain wall. Thus, observations of the circular polarization could give a stringent constraint on the characteristic CS length scale or could be a new avenue to search for axions.

We discuss the production of primordial gravitational waves (GW) from radiative inflaton decay during the period of reheating, assuming perturbative decay of the inflaton either into a pair of bosons or fermions, leading to successful reheating satisfying constraint from big bang nucleosynthesis. Assuming that the inflaton $\varphi$ oscillates in a general monomial potential $V(\varphi )\propto {\varphi }^n$, which results in a time-dependent inflaton decay width, we show that the resulting stochastic GW background can have optimistic detection prospects, especially in detectors that search for a high-frequency GW spectrum, depending on the choice of $n$ that determines the shape of the potential during reheating. We also discuss how this GW energy density may affect the measurement of $\mathrm{\Delta }{N}_{\mathrm{eff}}$ for bosonic and fermionic reheating scenarios.

In this paper, we investigate the interaction between early dark energy (EDE) and scalar field dark matter, proposing a coupled scalar fields model to address the Hubble tension and $S_8$ tension. While the EDE model successfully alleviates the Hubble tension, it exacerbates the $S_8$ tension. To mitigate the negative impact of EDE, we introduce the interaction between EDE and dark matter. Specifically, we replace cold dark matter with scalar field dark matter, given its capability to suppress structure growth on small scales. We constrained the new model using cosmological observations including the temperature and polarization anisotropy power spectra data of cosmic microwave background radiation from Planck 2018 results, baryon acoustic oscillations measurements extracted from 6dFGS, SDSS, and BOSS, the Pantheon sample of type Ia supernovae, the local distance-ladder data (SH0ES), and the Dark Energy Survey Year-3 data. Employing the Markov Chain Monte Carlo method, we find that this novel model yields best-fit values of $H_0$ and $S_8$ equal to $71.13\mathrm{km}/\mathrm{s}/\mathrm{Mpc}$ and 0.8256, respectively. Compared to the $\mathrm{\Lambda }\mathrm{CDM}$ model, the new model alleviates the Hubble tension but still fails to resolve the $S_8$ tension. However, we obtain a smaller value of $S_8$ compared to the result of 0.8316 obtained for EDE model, which mitigates to some extent the shortcoming of the EDE model.

Binary neutron star mergers probe the dense-matter equation of state (EoS) across a wide range of densities and temperatures, from the cold conditions of the inspiral to the high-temperature matter of the massive neutron star remnant. In this paper, we explore the sensitivity of neutron star mergers to uncertainties in the finite-temperature part of the EoS with a series of merger simulations performed in full general relativity. We expand on our previous work to explore the interplay between the thermal prescription and the stiffness of the zero-temperature EoS, which determines the compactness of the initial neutron stars. Using a phenomenological model of the particle effective mass, $M^{*}$, to calculate the finite-temperature part of the EoS, we perform merger simulations for a range of thermal prescriptions, together with two cold EoSs that predict either compact or large-radius initial neutron stars. We report on how the choice of $M^{*}$-parameters influences the thermal properties of the postmerger remnant, and how this varies for stars with different initial stellar compactness. We characterize the postmerger gravitational wave signals, and find differences in the peak frequencies of up to 190 Hz depending on the choice of $M^{*}$-parameters. Finally, we find that the total dynamical ejecta is in general only weakly sensitive to the thermal prescription, but that a particular combination of $M^{*}$-parameters, together with a soft cold EoS, can lead to significant enhancements in the ejecta.

Our study investigates the complex interaction between active neutrinos and the ultralight bosonic dark matter halo surrounding the Sun. This halo extends over several solar radii due to the Sun’s gravitational field, and we represent it as a coherent oscillating classical field configuration of bosonic dark matter particles that vary in time. Our investigation has revealed that, based on the available solar neutrino flux data, these novel models do not surpass the performance of the conventional neutrino flavour oscillation model. Furthermore, we discuss how next-generation solar neutrino detectors have the potential to provide evidence for the existence or absence of the ultralight-dark matter halo.

Motivated by the recent experimental progress in the ${\mathrm{\Lambda }}_c$ decay that contains a neutron in the final state, we analyze the semileptonic decay ${\mathrm{\Lambda }}_c\to n\ell {\nu }_{\ell }$ in the framework of QCD sum rules. The transition form factors are analytically computed using three-point correlation functions and the Cutkosky cutting rules, which can be extrapolated into the physical region by employing the $z$-series parametrization. The branching fractions of ${\mathrm{\Lambda }}_c\to n{e}^{+}{\nu }_e$ and ${\mathrm{\Lambda }}_c\to n{\mu }^{+}{\nu }_{\mu }$ are estimated to be $(0.281\pm 0.056)\%$ and $(0.275\pm 0.055)\%$, respectively. Furthermore, we calculate as well the relevant decay asymmetry observables sensitive to new physics beyond the standard model. The numerical results of semileptonic decays ${\mathrm{\Lambda }}_c\to \mathrm{\Lambda }\ell {\nu }_{\ell }$ are also given and confronted to the latest experimental data.

We investigate the properties of the fermionic Fulling-Rindler vacuum for a massive Dirac field in a general number of spatial dimensions. As important local characteristics, the fermionic condensate and the expectation value of the energy-momentum tensor are evaluated. The renormalization is reduced to the subtraction of the corresponding expectation values for the Minkowski vacuum. It is shown that the fermion condensate vanishes for a massless field and is negative for nonzero mass. Unlike the case of scalar fields, the fermionic vacuum stresses are isotropic for the general case of massive fields. The energy density and the pressures are negative. For a massless field, the corresponding spectral distributions exhibit thermal properties with the standard Unruh temperature. However, the density-of-states factor is not Planckian for a general number of spatial dimensions. Another interesting feature is that the thermal distribution is of the Bose-Einstein type in an even number of spatial dimensions. This feature has been observed previously in the response of a particle detector uniformly accelerating through the Minkowski vacuum. In an even number of space dimensions, the fermion condensate and the mean energy-momentum tensor coincide for the fields, realizing two inequivalent irreducible representations of the Clifford algebra. In the massless case, we consider also the vacuum energy-momentum tensor for Dirac fields in the conformal vacuum of the Milne universe, in the static open universe, and in the hyperbolic vacuum of de Sitter spacetime.

Ordinary Hermitian $\lambda {\varphi }^4$ theory is known to exist in $d<4$ dimensions when $\lambda >0$. For negative values of the coupling, it has been suggested that a physical meaningful definition of the interacting theory can be given in terms of $\mathcal{P}T$-symmetric field theory. In this work, we critically reexamine the relation between analytically continued Hermitian field theory with quartic interaction and $\mathcal{P}T$-symmetric field theory, including $O(N)$ models. We find that in general $\mathcal{P}T$-symmetric field theory does not correspond to the analytic continuation of the Hermitian theory to negative coupling, except at high temperature where the instanton contribution present in the analytically continued theory can be neglected.

The center of the Milky Way is a prime site to search for signals of dark matter (DM) annihilation due to its proximity and expected high concentration of DM. The amplification of the dispersion velocity of DM particles in the Galactic Center (GC), caused by baryonic contraction and feedback, makes this particular region of the sky an even more promising target for exploring velocity-dependent DM models. Here we demonstrate that current GC observations with the H.E.S.S. telescope, presently the most sensitive TeV-scale gamma-ray telescope in operation in this region of the sky, set the strongest constraints on velocity-dependent annihilating DM particles with masses above 200 GeV. For p-wave annihilations, they improve the current constraints by a factor of $\sim 4$ for a DM mass of 1 TeV. For the spatial distribution of DM, we use the results of the latest FIRE-2 zoom cosmological simulation of Milky Way-size halos. In addition, we utilize the newest version of the galprop cosmic-ray propagation framework to simulate the Galactic diffuse gamma-ray emission in the GC. We have found that p-wave (d-wave) DM particles with a mass of approximately 1.7 TeV and annihilating into the $W^{+}{W}^{-}$ channel exhibit a velocity-weighted annihilation cross-section upper limit of $4.6\times {10}^{-22}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$ ($9.2\times {10}^{-17}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$) at a 95% confidence level. This is about 460 ($2\times {10}^6$) times greater than the thermal relic cross section for p-wave (d-wave) DM models.

We constrain a broad class of “hairy” black hole models capable of directly sourcing electromagnetic radiation during a binary black hole merger. This signal is generic and model-independent since it is characterized by the black hole mass ($M$) and the fraction of that mass released as radiation ($\epsilon$). For field energy densities surpassing the Schwinger limit, this mechanism triggers pair production to produce a gamma-ray burst. By cross-referencing gravitational wave events with gamma-ray observations, we place upper bounds of $\epsilon <{10}^{-5}–{10}^{-4}$ for $10–50M_{\odot }$ black holes depending on the black hole mass. We discuss the weak detection of a gamma-ray burst following GW150914 and show that this event is consistent with rapid electromagnetic emission directly from a hairy black hole with $\epsilon \sim {10}^{-7}–{10}^{-6}$. Below the Schwinger limit, ambient charged particles are rapidly accelerated to nearly the speed of light by the strong electromagnetic field. For $1–50M_{\odot }$ black holes and $\epsilon$ ranging from ${10}^{-20}$ to ${10}^{-7}$, the typical proton energies are $\sim 20\mathrm{GeV}–20\mathrm{TeV}$ and electron energies are $\sim 0.01–10\mathrm{GeV}$. At these energies, cosmic ray protons and electrons quickly diffuse into the Milky Way’s background magnetic field, making it difficult to identify a point source producing them. Overall, constraining $\epsilon$ in this less energetic regime becomes difficult and future constraints may need to consider specific models of hairy black holes.

We study the time evolution of the numbers of charm mesons after the kinetic freeze-out of the expanding hadron gas produced by the hadronization of the quark-gluon plasma from a central heavy-ion collision. The $\pi D$ reaction rates have contributions from a $D^{*}$ resonance in the $s$ channel. The $\pi D^{*}$ reaction rates are enhanced by $t$-channel singularities from an intermediate $D$. The contributions to reaction rates from $D^{*}$ resonances and $D$-meson $t$-channel singularities are sensitive to thermal mass shifts and thermal widths. In the expanding hadron gas, the $t$-channel singularities are regularized by the thermal $D$ widths. After kinetic freeze-out, the thermal $D$ widths are dominated by coherent pion forward scattering. The contributions to $\pi D^{*}$ reaction rates from $t$-channel singularities are inversely proportional to the pion number density, which decreases to 0 as the hadron gas expands. The $t$-channel singularities produce small but significant changes in charm-meson ratios from those predicted using the known $D^{*}$-decay branching fractions.

We derive equations of motion for dissipative spin hydrodynamics from kinetic theory up to first order in a gradient expansion. Choosing a specific form of the matching conditions, relating the change in the spin potential to the spin diffusion and spin energy, we then show that the equations of motion, linearized around homogeneous global equilibrium, are causal and stable in any Lorentz frame, if certain sufficient conditions on the transport coefficients are fulfilled.