We discuss the negativity of the moment of inertia of (quark-)gluon plasma in a window of “supervortical” range of temperatures above the deconfining phase transition, $T\simeq (1\dots 1.5)T_c$, found recently in numerical Monte Carlo simulations by two independent methods. In our work, we confirm numerically that the origin of this effect is rooted in the thermal evaporation of the nonperturbative chromomagnetic condensate. We argue that the negative moment of inertia of gluon plasma indicates the presence of a novel effect, the negative spin-vortical coupling for gluons resulting in a negative gluonic Barnett effect: the spin polarization of gluons exceeds the total angular momentum of rotating plasma, thus forcing the orbital angular momentum to take negative values in the supervortical range of temperatures.

We construct symmetry-preserving lattice regularizations of 2D QED with one and two flavors of Dirac fermions, as well as the “3450” chiral gauge theory, by leveraging bosonization and recently proposed modifications of Villain-type lattice actions. The internal global symmetries act just as locally on the lattice as they do in the continuum, the anomalies are reproduced at finite lattice spacing, and in each case we find a sign-problem-free dual formulation.

We present a determination of the structure functions of the off-forward Compton amplitude ${\mathcal{H}}_1$ and ${\mathcal{E}}_1$ from the Feynman-Hellmann method in lattice QCD. At leading twist, these structure functions give access to the generalized parton distributions (GPDs) $H$ and $E$, respectively. This calculation is performed for an unphysical pion mass of $m_{\pi }=412\mathrm{MeV}$ and four values of the soft momentum transfer, $t\approx 0,-0.3,-0.6,-1.1{\mathrm{GeV}}^2$, all at a hard momentum scale of ${\overline{Q}}^2\approx 5{\mathrm{GeV}}^2$. Using these results, we test various methods to determine properties of the real-time scattering amplitudes and GPDs: (1) we fit their Mellin moments, and (2) we use a simple GPD ansatz to reconstruct the entire distribution. Our final results show promising agreement with phenomenology and other lattice results and highlight specific systematics in need of control.

QCD bounds on the leading-order (LO) hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon [$a_{\mu }^{\mathrm{HVP},\mathrm{LO}}$, $a_{\mu }={(g-2)}_{\mu }/2$] are determined by imposing Hölder inequalities and related inequality constraints on systems of finite-energy QCD sum rules. This novel methodology is complementary to lattice QCD and data-driven approaches to determining $a_{\mu }^{\mathrm{HVP},\mathrm{LO}}$. For the light-quark ($u$, $d$, $s$) contributions up to five-loop order in perturbation theory in the chiral limit, LO in light-quark mass corrections, next-to-leading order in dimension-four QCD condensates, and to LO in dimension-six QCD condensates, we find that $(657.0\pm 34.8)\times {10}^{-10}\le a_{\mu }^{\mathrm{HVP},\mathrm{LO}}\le (788.4\pm 41.8)\times {10}^{-10}$, bridging the range between lattice QCD and data-driven values.

We present results for the ${\tau }_1$ and ${\tau }_{1a}$ 1-jettiness global event shape distributions, for deep inelastic scattering (DIS), at the ${\mathrm{N}}^3\mathrm{LL}+\mathcal{O}({\alpha }_s^2)$ level of accuracy. These event-shape distributions quantify and characterize the pattern of final state radiation in electron-nucleus collisions. They can be used as a probe of nuclear structure functions, as nuclear medium effects in jet production, and for a precision extraction of the QCD strong coupling. The results presented here, along with the corresponding numerical codes, can be used for analyses with HERA data, in Electron-Ion Collider (EIC) simulation studies, and for eventual comparison with real EIC data.

The bounds on the light quark masses are obtained by fitting the squares of pseudoscalar meson masses $m_{\pi }^2$ and $m_K^2$ to second order in $1/N_c$ expansion. The result is an algebraic cubic curve whose coefficients are the known Weinberg values for the quark mass ratios $m_u/m_d$ and $m_s/m_d$. Additional restrictions arise when using the ratio $m_s/m_{ud}=27.23(10)$ quoted by FLAG for lattice simulations with four quark flavors. This provides a tight constraint on the ratio $m_u/m_d=0.455(8)$.

In this paper, we report the results of our study on the nuclear medium modifications of the meson electromagnetic form factors in the framework of the Nambu–Jona-Lasinio model with the help of the Schwinger proper-time regularization scheme to tame the loop divergence and simulate the effect of QCD confinement. In our current approach, the meson structure and nuclear medium are constructed in the same Nambu–Jona-Lasinio model at the quark level. We examine the free-space and in-medium charge radii of kaon and pion, the spacelike elastic electromagnetic form factors of kaon and pion, and their quark-sector form factors, which reflect their internal structures. By comparing our result to experimental data, we found that the free-space elastic electromagnetic form factors of the mesons are consistent with the data, while the in-medium elastic electromagnetic form factors of the mesons are found to decrease as the nuclear matter density increases, leading to a rise of meson charge radius, which is consistent with the prediction of other theoretical calculations. We also predict the axial nucleon coupling constant $g_A$ in nuclear medium computed via the Goldberger-Treiman relation, which is crucial for searching the neutrinoless double beta decay ($0\nu \beta \beta$).

In an earlier analysis [Sen et al., Phys. Rev. D 105, 085007 (2022)], we explored the event of acceleration radiation for an atom freely falling into the event horizon of a quantum corrected Schwarzschild black hole. We want to explore the acceleration-radiation when the atom is freely falling into the event horizon of a charged quantum corrected black hole. We consider the quantum effects of the electromagnetic field along with the gravitational field in an asymptotic safety regime. Introducing the quantum-improved Reissner-Nordström metric, we have calculated the excitation probability of a two-level atom freely falling into the event horizon of quantum-improved charged black hole. Recently, in the case of the braneworld black hole (where the tidal charge has the same dimension as the square of the charge of a Reissner-Nordström black hole in natural units), we have observed from the form of the transition probability that the temperature will have no contribution in the first order of the tidal charge. We observe that for a quantum corrected Reissner-Nordström black hole, there is a second-order contribution in the charge parameter in the temperature that can be read off from the transition probability. Next, we calculate the horizon-brightened acceleration radiation (HBAR) entropy in this thought experiment and show that this entropy has a leading-order Bekenstein-Hawking entropy term along with some higher-order correction terms involving logarithmic as well as fractional terms of the black hole area due to infalling photons. We have finally investigated the validity of Wien’s displacement law and compared the critical value of the field wavelength with the general Schwarzschild black hole and its corresponding quantum corrected case.

Flying mirrors with appropriate trajectories have been recognized as an analog system that mimics black hole Hawking evaporation and have been widely investigated. It has recently been suggested that the partner mode of the analog Hawking radiation emitted from a moving mirror would manifest itself through a final burst when the mirror executes a sudden stop. Here we argue the opposite via the partner formula for the moving mirror model. By expanding the theoretical foundation of the partner formula and augmenting it with numerical analysis, we demonstrate that the supposed final burst is induced by a shock that requires the input of external energy, whereas the Hawking radiation partner mode, which is associated with the zero-point vacuum fluctuations, is not responsible for the burst.

To fully exploit the data from next generation surveys, we need an accurate modeling of the matter power spectrum up to nonlinear scales. Therefore in this work we present the halo model reaction framework for the generalized cubic covariant Galileon (GCCG) model, a modified gravity model within the Horndeski class of theories which extends the cubic covariant Galileon (G3) by including power laws of the derivatives of the scalar field in the K-essence and cubic terms. We modify the publicly available software react for the GCCG in order to obtain an accurate prediction of the nonlinear power spectrum. In the limit of the G3 model we compare the modified react code to $N$-body simulations and we find agreement within 5% for a wide range of scales and redshifts. We then study the relevant effects of the modifications introduced by the GCCG on the nonlinear matter power spectrum. Finally, we provide forecasts from spectroscopic and photometric primary probes by next generation surveys using a Fisher matrix method. We show that future data will be able to constrain at $1\sigma$ the two additional parameters of the model at the percent level and that considering nonlinear corrections to the matter power spectrum beyond the linear regime is crucial to obtain this result.

We evaluate the possibility of the formation of naked singularities in the interaction of Kerr black holes with test massless spin-2 fields. We analyze the scattering problem for both extremal and nearly extremal black holes by incorporating the explicit form of the absorption probabilities. We show that extremal black holes become nonextremal after the interaction with the modes with both positive and negative absorption probabilities. For nearly extremal black holes the absorption probability for the challenging modes turns out to be of the order ${\epsilon }^5$, where $\epsilon$ parametrizes the closeness to extremality. Though the highest absorption probability for $m=2$ modes pertains to spin-2 fields, its drastically small value implies that the event horizon is preserved without the need to employ the backreaction effects. The result can be qualitatively extrapolated to hypothetical higher integer spin fields. We also review and extend our previous comments on Sorce-Wald method. We show that the order magnitude problems can be avoided by abandoning the nonphysical parameter $\lambda$. The conditions derived by Sorce-Wald can be legitimately used to incorporate the backreaction effects by avoiding to multiply them by ${\lambda }^2$, thereby preserving the magnitude of their contribution. We apply this method to the problems of overcharging Reissner-Nordström black holes and overspinning Kerr black holes, in a rough analysis ignoring absorption probabilities which could apply to test bodies.

We employ the approach of path integral in the “phase space” to study the kinetics of state switching associated with black hole phase transitions. Under the assumption that the state switching process of the black hole is described by the stochastic Langevin equation based on the free energy landscape, we derived the Martin–Siggia–Rose–Janssen–de Dominicis (MSRJD) functional and obtained the path integral expression of the transition probability. The MSRJD functional inherently represents the path integral in the “phase space,” allowing us to extract the effective Hamiltonian for the dynamics of the state switching process. By solving the Hamiltonian equations of motion, we obtain the kinetic path in the “phase space” using an example of the Reissner-Nordstrom anti-de Sitter black hole. Furthermore, the dominant kinetic path within the configuration space is calculated. We also discuss the kinetic rate by using the functional formalism. Finally, we examine two further examples: Hawking-Page phase transition and Gauss-Bonnet black hole phase transition at the triple point. Our analysis demonstrates that, concerning the Hawking-Page phase transition, while a dominant kinetic path in the “phase space” from the large Schwartzschild anti-de Sitter black hole to the thermal anti–de Sitter space is present, there is no kinetic path for the inverse process. For the Gauss-Bonnet black hole phase transition at the triple point, the state switching processes between the small, the intermediate and the large Gauss-Bonnet black holes constitute a “chemical reaction cycle.”

In this paper we study the qualitative features induced by corrections to general relativity (GR) coming from string theory, on the shadows of rotating black holes. We research the slowly rotating black hole solutions up to order $\mathcal{O}(a^3)$, to first order in ${\alpha }^{\prime }$, also including the dilaton. We provide a detailed characterization of the geometry, as well as the innermost stable circular orbit (ISCO) and photon ring; then, we proceed to obtain the black hole images within the relativistic thin-disk model. We characterize the images by computing the diameter, displacement, and asymmetry. A comparison with the Kerr case indicates that all these quantities grow due to the ${\alpha }^{\prime }$ correction and that the departure from GR for different observables is enhanced depending on the angle of view; namely, for the diameter, the maximum departure is obtained when the system is face-on, while for the displacement and asymmetry, the departure from GR is maximized for the edge-on point of view.

In this paper, we investigate the gravitational lensing effect for the Schwarzschild-like black hole space-time in the background of a Kalb-Ramond (KR) field proposed by Yang et al. [Phys. Rev. D 108, 124004 (2023)]. The solution is characterized by a single extra parameter $l$, which is associated to the Lorentz symmetry breaking induced by the KR field. First, we calculate the exact deflection angle of massive and massless particles for finite distances using elliptic integrals. Then we study this effect in the weak and strong field regimes, discussing the correction of the KR parameter on the coefficients of the expansions in both limits. We also find that increasing $l$ decreases the deflection angle. Furthermore, we use the available data from the Sagittarius $A^{\star }$ object, which is believed to be a supermassive black hole at the center of our Galaxy, to calculate relevant observables, such as the image position, luminosity, and delay time. The values found could be potentially measured in the weak field regime, though for strong fields one would have to wait for the next generation of interferometers.

Gravitational-wave (GW) observations of neutron star-black hole (NSBH) mergers are sensitive to the nuclear equation of state (EOS). We present a new methodology for EOS inference with nonparametric Gaussian process priors, enabling direct constraints on the pressure at specific densities and the length-scale of correlations on the EOS. Using realistic simulations of NSBH mergers, incorporating both GW and electromagnetic selection to ensure sample purity, we find that a GW detector network operating at O5 sensitivities will constrain the radius of a $1.4M_{\odot }$ NS and the maximum NS mass with 1.6% and 13% precision, respectively. With the same sample, the projected constraint on the length-scale of correlations in the EOS is $\ge 3.2\mathrm{MeV}{\mathrm{fm}}^{-3}$. These results demonstrate strong potential for insights into the nuclear EOS from NSBH systems, provided they are robustly identified.

Predicting the 21-cm signal from the epoch of reionization and cosmic dawn is a complex and challenging task. Various simplifying assumptions have been applied over the last decades to make the modeling more affordable. In this paper, we investigate the validity of several such assumptions, using a simulation suite consisting of three different astrophysical source models that agree with the current constraints on the reionization history and the UV luminosity function. We first show that the common assumption of a saturated spin temperature may lead to significant errors in the 21-cm clustering signal over the full reionization period. The same is true for the assumption of a neutral universe during the cosmic dawn which may lead to significant deviation from the correct signal during the heating and the Lyman-$\alpha$ coupling period. Another popular simplifying assumption consists of predicting the global differential brightness temperature ($d{T}_b$) based on the average quantities of the reionization fraction, gas temperature, and Lyman-$\alpha$ coupling. We show that such an approach leads to a 10 percent deeper absorption signal compared to the results obtained by averaging the final $d{T}_b$-map. Finally, we investigate the simplifying method of breaking the 21-cm clustering signal into different auto and cross components that are then solved assuming linearity. We show that even though the individual fields have a variance well below unity, they often cannot be treated perturbatively as the perturbations are strongly non-Gaussian. As a consequence, predictions based on the perturbative solution of individual auto and cross power spectra may lead to strongly biased results, even if higher-order terms are taken into account.

We consider a light scalar dark matter candidate with mass in the GeV range whose $p$-wave annihilation is enhanced through a Breit-Wigner resonance. The annihilation actually proceeds in the $s$-channel via a dark photon mediator whose mass is nearly equal to the masses of the incoming particles. We compute the temperature at which kinetic decoupling between dark matter and the primordial plasma occurs and show that including the effect of kinetic decoupling can reduce the dark matter relic density by orders of magnitude. For typical scalar masses ranging from 200 MeV to 5 GeV, we determine the range of values allowed for the dark photon couplings to the scalar and to the standard model particles after requiring the relic density to be in agreement with the value extracted from cosmological observations. We then show that $\mu$ and $y$-distortions of the cosmic microwave background spectrum and x-ray data from XMM-Newton strongly constrain the model and rule out the region where the dark matter annihilation cross section is strongly enhanced at small dispersion velocities. Constraints from direct detection searches and from accelerator searches for dark photons offer complementary probes of the model.

Precession in binary black holes (BBH) is caused by the failure of the black hole spins to be aligned and its study can open up new perspectives in gravitational wave astronomy, providing, among other advancements, a precise measure of distance and an accurate characterization of the BBH spins. However, detecting precessing signals is a highly nontrivial task, as standard matched filtering pipelines for gravitational wave searches are built on many assumptions that do not hold in the precessing case. This work details the upgrades made to the GstLAL pipeline to facilitate the search for precessing BBH signals. The implemented changes in the search statistics and in the signal consistency test are then described in detail. The performance of the upgraded pipeline is evaluated through two extensive searches of precessing signals, targeting two different regions in the mass space, and the consistency of the results is examined. Additionally, the benefits of the upgrades are assessed by comparing the sensitive volume of the precessing searches with two corresponding traditional aligned-spin searches. While no significant sensitivity improvement is observed for precessing binaries with mass ratio $q\lesssim 6$, a volume increase of up to 100% is attainable for heavily asymmetric systems with largely misaligned spins. Furthermore, our findings suggest that the primary cause of degraded performance in an aligned-spin search targeting precessing signals is not a poor signal-to-noise-ratio recovery but rather the failure of the ${\xi }^2$ signal-consistency test. Our work paves the way for a large-scale search for precessing signals, which could potentially result in exciting future detections.

We provide a step-by-step method to construct skyrmions from instanton ADHM data, including when the exact ADHM data is unknown. The configurations look like clusters of smaller skyrmions, and can be used to build manifolds of skyrmions with or without symmetries. Nuclei are described by quantum states on these manifolds. We describe the construction and quantization procedure generally, then apply the methods in detail to the 8-skyrmion which describes the Beryllium-8 nucleus.

We study the prospects of thermal leptogenesis in the framework of the minimal flipped $SU(5)$ unified model in which the right-handed (RH) neutrino mass scale emerges as a two-loop effect. Despite its strong suppression with respect to the unification scale that tends to disfavor leptogenesis in the standard Davidson-Ibarra regime (and a notoriously large washout of the $N_1$-generated asymmetry owing to a toplike Yukawa entry in the Dirac neutrino mass matrix) the desired ${\eta }_B\sim 6\times {10}^{-10}$ can still be attained in several parts of the parameter space exhibiting interesting baryon and lepton number violation phenomenology. Remarkably enough, in all these regions the mass of the lightest left-handed (LH) neutrino is so low that it yields $m_{\beta }\lesssim 0.03\mathrm{eV}$ for the effective neutrino mass measured in beta decay, i.e., an order of magnitude below the design sensitivity limit of the KATRIN experiment. This makes the model potentially testable in the near future.