We present an analysis of the time-dependent modulation of galactic cosmic rays near Earth, with a focus on the cosmic proton flux and polar field. Using data from the Alpha Magnetic Spectrometer (AMS) and the Wilcox Solar Observatory, we identify a significant time-lagged relationship between the observation of two missions. Our model incorporates a weighted magnetic field parameter to address the hemispheric asymmetry in polar fields and captures the temporal evolution of cosmic ray proton spectra in relation to solar activity. We find a time lag of approximately 10 months, varying with cosmic ray rigidity. At 1 GV, the time lag is 360 days, while it is 300 days above 3 GV. A potential mechanism is proposed to explain the observed time-lagged relationship and its dependence on cosmic ray rigidity. This offers predictive insights into cosmic ray modulation within the heliosphere. These results enhance the accuracy of space weather forecasting models, with significant implications for the safety of space missions and aviation.

The long-term variability study over a range of black hole mass systems from the microquasars of stellar-mass black holes to the active galactic nuclei (AGNs) of supermassive black holes, in $\gamma$ rays offers new insights into the physics of relativistic jets. In this work, we investigate the $\gamma$-ray variability of 11 AGNs–including seven blazars, two unclassified blazar candidates, one radio galaxy, and one narrow-line Seyfert 1 galaxy, along with two microquasars. We employ the damped random walk stochastic process to model approximately 15 years of Fermi-Large Area Telescope (LAT) light curves, revealing rest-frame timescales ranging from 40 to 400 days. The characteristic timescales observed in AGNs are comparable to the optical timescales of accretion disks. Notably, the timescales of jet emission in microquasars closely resemble those of AGNs, indicating consistent jet properties across black holes of all masses. The observed rest-frame timescales $({\tau }_{\mathrm{DRW}}^{\mathrm{rest}})$ in AGNs overlap with both thermal and nonthermal timescales associated with the accretion disk and jet, respectively, suggesting a scaled relationship between ${\tau }_{\mathrm{DRW}}^{\mathrm{rest}}$ and black hole mass (${\mathrm{M}}_{\mathrm{BH}}$). Although the rest-frame gamma-ray timescales of microquasars deviate significantly from the ${\tau }_{\mathrm{DRW}}^{\mathrm{rest}}\text{−}{\mathrm{M}}_{\mathrm{BH}}$ relation observed in AGNs, they still follow a distinct scaling with ${\mathrm{M}}_{\mathrm{BH}}$ in the gamma rays explicitly. These findings offer new insights into the origin of jets and their emission processes. Furthermore, this study suggests an alternative perspective that the properties of relativistic jets or their emission mechanisms may be independent of black hole mass.

Amaterasu, the second most energetic (244 EeV) cosmic ray particle has been recently detected by the Telescope Array (TA) surface detector. The origin of the TA Amaterasu event is puzzling, as its arrival direction points back to a void in the local Universe, lacking conventional astrophysical ultrahigh-energy (UHE) cosmic ray sources. Hence, we explore the possibility if this TA Amaterasu event could have originated from the decay of superheavy dark matter (SHDM) in the Milky Way. Such an origin also opens up multimessenger detection channels in both UHE gamma rays and UHE neutrinos. In this present work, using the TA Amaterasu event and the multimessenger limits/sensitivities from various UHE telescopes, we place stringent constraints on the lifetime and mass of the SHDM. We find that the nondetection of the corresponding gamma rays at the Pierre Auger Observatory (PAO) and the TA is in severe tension with the SHDM parameter space required to explain the TA Amaterasu event. Additionally, we extend the multimessenger analysis to the future UHE gamma-ray and UHE neutrino telescopes such as PAO upgrade, GRAND 200k, and IceCube-Gen2. We find that the bounds from the future neutrino telescopes will be able to compete with the present UHECR bounds. However, compared to the existing UHE gamma-ray bounds, the future PAO upgrade and the GRAND 200k gamma-ray detectors will improve the bounds on SHDM lifetime by at least one order of magnitude.

This paper investigates the potential of intensity interferometry, based on the Hanbury Brown-Twiss effect, for measuring supernova sizes and distances. With optimized telescope positioning, observing strategy, and advancements in single-photon detection technology, this method can provide precise angular size measurements of supernovae with apparent magnitudes as bright as 12 mag. For type Ia supernovae, this limiting brightness corresponds to a local volume extending to redshift $z\sim 0.004$ and an anticipated discovery rate of approximately 1 event per year. The combination of angular size data with known physical dimensions enables accurate distance determination. Multiple telescope pairs at different relative positions allow tomographic mapping of the ejecta structure while reducing distance uncertainties. As type Ia supernovae serve as standardizable candles for measuring the Universe’s expansion history, combining intensity interferometry distances with the supernova Hubble diagram facilitates measurements of the Hubble constant $H_0$.

Light sterile neutrinos, ${\nu }_s$, are often introduced to explain an anomalous deficit in the electron antineutrino flux from nuclear reactors. If they exist, sterile neutrinos would also be produced in collapsing massive stars through the active-sterile neutrino oscillation. In order to investigate the impacts of sterile neutrinos on supernova dynamics, we perform two-dimensional neutrino-radiation hydrodynamic simulations of stellar core-collapse coupled with the active-sterile oscillation through the Mikheyev–Smirnov–Wolfenstein effect. As the initial condition of our simulations, we adopt a blue supergiant model that is tuned to reproduce observational features of the SN 1987A progenitor to compare our models with observations of the event. It is found that the active-sterile oscillation reduces the ${\nu }_e$ and ${\overline{\nu }}_e$ fluxes and decreases the explosion energy. We also find that, if the mixing angle $\theta$ and the mass difference $\delta m_{\mathrm{s}}^2$ between ${\nu }_e$ and ${\nu }_s$ are large enough, the star fails to explode. This suggests that these mixing parameters relevant to sterile neutrinos could be constrained by supernova explodability, though other uncertainties in supernova theory need to be addressed to refine them. In addition, we predict neutrino signals from a nearby supernova event and find that the neutrino event number can significantly decrease because the ${\nu }_e$ and ${\overline{\nu }}_e$ fluxes are reduced. In particular, DUNE observations of ${\nu }_e$ will be useful to search for a signature of sterile neutrinos with a tiny mixing angle because a smaller mixing angle leads to a larger effect on the ${\nu }_e$ flux.

The multiwavelength polarized light signals from supermassive black holes have sparked many studies on polarized images of accretion disks and hot spots. However, the polarization patterns within the innermost stable circular orbit (ISCO) region remain to be explored. In this study, we focus on two specific types of orbits, namely the plunging geodesics inward from the ISCO and homoclinic geodesics, to uncover the polarization features associated with noncircular motion in a Kerr spacetime. For an on-axis observer, we specifically develop an approximate function to describe gravitational lensing along the azimuthal direction and establish a simplified synchrotron emission model. Based on these, we analyze the time-integrated polarized images of hot spots and their Stokes parameters. Moreover, we explore the polarized image of the plunging region within a thin accretion disk.

Extreme-mass-ratio inspirals (EMRIs) are one of the key targets for future space-based gravitational wave detectors, such as LISA. The scientific potential of these sources can only be fully realized with fast and accurate waveform models. In this work, we extend the fastemriwaveform (few) framework by providing fully relativistic waveforms at adiabatic order for circular, equatorial orbits in Kerr spacetime, for mass ratios up to ${10}^{-3}$. We investigate the significance of including relativistic corrections in the waveform for both vacuum and nonvacuum environments. Specifically, we develop relativistic nonvacuum EMRI waveforms including two different environmental effects in the EMRI waveforms: power-law migration torques and superradiance scalar clouds. For EMRIs in vacuum, we find that nonrelativistic waveforms incorrectly estimate the predicted source’s horizon redshift by approximately 35% error. Our analysis shows that incorporating relativistic corrections enhances constraints on accretion disks, modeled through power-law torques, and improves the constraints on disk parameter estimates (error $\simeq 8\%$), representing a significant improvement over previous estimates. Additionally, we assess the evidence for models in a scenario where ignoring the accretion disk biases the parameter estimation, reporting a ${\log }_{10}$ Bayes factor of 1.1 in favor of the accretion disk model. In a fully relativistic setup, we also estimate the parameters of superradiant scalar clouds with relative errors $\simeq 0.3\%$ for the scalar cloud’s mass. These results demonstrate that incorporating relativistic effects is essential for Laser Interferometer Space Antenna science objectives with EMRIs.

Subnuclear fluctuations in the initial state of heavy-ion collisions impact not only transverse long-range correlations of small systems, but also the creation of longitudinal structures, seen in particle detectors as longitudinal decorrelation observables. In this work, we study the emergence of long-range rapidity correlations in nuclear collisions based on the 3D resolved McDipper initial state model, and for the first time, connect it to experimental observables using the $3+1\mathrm{D}$ viscous hydrodynamics framework CLVisc. We include different sources of fluctuations at the nucleon and subnucleon level and study the effects of these additional fluctuation sources on the longitudinal structure of relevant observables, such as the flow decorrelations and directed flow.

In this article, we analyze the effects of stochastic spatial magnetic fluctuations with respect to an intense uniform average magnetic field background over the yields for photon and dilepton emission processes in a thermalized quark-gluon plasma phase. Such stochastic fluctuations model the effects of nearly random initial conditions for the nuclei participating in noncentral heavy-ion collisions, which are the sources of the background magnetic field. Our theoretical results predict significant anisotropic effects due to stochastic magnetic noise over the angular distribution for photon and dilepton production rates in this scenario.

We consider the spontaneous breaking of $SO(10)$ grand unified symmetry to the left-right symmetric model $SU(3{)}_c\times SU(3{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$ with C-parity also unbroken [$C$ converts $Q\to -Q$, where $Q$ is the electric charge operator in $SO(10)$.] This breaking produces the topologically stable grand unified theory (GUT) monopole as well as a GUT scale C-string. The subsequent breaking at an intermediate scale of C-parity produces domain walls bounded by C-strings, found by Kibble et al. A limited number of inflationary $e$-foldings experienced during these breakings can yield an observable number density of primordial GUT monopoles. The C-strings also experience this inflationary phase, and the subsequent string-wall network decays through the emission of gravitational waves. We estimate the gravitational wave spectrum from these composite structures over a range of values of the domain wall tension $\sigma$. Depending on $\sigma$ the spectrum displays a peak in the higher frequency range between ${10}^2$ and ${10}^5\mathrm{Hz}$.

The construction of gauge-invariant states of SU(3) lattice gauge theories has garnered new interest in recent years, but implementing them is complicated by the need for SU(3) Clebsch-Gordon coefficients. In the loop-string-hadron (LSH) approach to lattice gauge theories, the elementary excitations are strictly gauge invariant, and constructing the basis requires no knowledge of Clebsch-Gordon coefficients. Originally developed for SU(2), the LSH formulation was recently generalized to SU(3), but limited to one spatial dimension. In this work, we generalize the LSH approach to constructing the basis of SU(3) gauge-invariant states at a trivalent vertex—the essential building block to multidimensional space. A direct generalization from the SU(2) vertex yields a legitimate basis; however, in certain sectors of the Hilbert space, the naive LSH basis vectors so defined suffer from being nonorthogonal. The issues with orthogonality are directly related to the “missing label” or “outer multiplicity” problem associated with SU(3) tensor products and may also be phrased in terms of Littlewood-Richardson coefficients or the need for a “seventh Casimir” operator. The states that are unaffected by the problem are orthonormalized in closed form. For the sectors that are afflicted, we discuss the nonorthogonal bases and their orthogonalization. A few candidates for seventh Casimir operators are readily constructed from the suite of LSH gauge-singlet operators. The diagonalization of a seventh Casimir represents one prescriptive solution toward obtaining a complete orthonormal basis, but a closed-form general solution remains to be found.

We present a first-order dissipative spin hydrodynamic framework, where the spin chemical potential ${\omega }^{\mu \nu }$ is treated as the leading term in the hydrodynamic gradient expansion, i.e., ${\omega }^{\mu \nu }\sim \mathcal{O}(1)$. We argue that for the consistency of the theoretical framework, the energy-momentum tensor needs to be symmetric at least up to order $\mathcal{O}(\partial )$. We consider the phenomenological form of the spin tensor, where it is antisymmetric in the last two indices only. A comprehensive analysis of spin hydrodynamics is conducted using both macroscopic entropy current analysis and microscopic Kubo formalism, establishing consistency between the two approaches. A key finding is the entropy production resulting from spin-orbit coupling, which alters the traditional equivalence between the Landau and Eckart fluid frames. Additionally, we identify cross-diffusion effects, where vector dissipative currents are influenced by gradients of both spin chemical potential and chemical potential corresponding to the conserved charge through off-diagonal transport coefficients. Two distinct methods for decomposing the spin tensor are proposed, and their equivalence is demonstrated through Kubo relations.

We investigate the contribution of the charm-anticharm ($c\overline{c}$) asymmetry of the proton eigenstate obtained from QCD lattice gauge to the asymmetry of $D^{+},D^{-}$ and $D^0,{\overline{D}}^0$ mesons produced in $pp$ collisions at large Feynman variables $x$. It is shown that an important tool for establishing the intrinsic charm (IC) content of the proton is the charm hadron-antihadron asymmetry formed in $pp$ collisions. Predictions for the asymmetry as a function of $x$ for different IC probabilities are presented. We show that the interference of the intrinsic $|uudc\overline{c}⟩$ Fock state with the standard contribution from the perturbative QCD evolution leads to a large $D^{+}{D}^{-}$ asymmetry at large Feynman $x$.

We calculate the kinematic twist-3 and twist-4 corrections to the leading-order amplitude of timelike Compton scattering (TCS) on a (pseudo)scalar target, in the recently developed framework based on the conformal operator-product expansion. This allows us to compute the complete set of helicity amplitudes of the process, in particular those that vanish at leading twist. We compare the effects of higher-twist contributions to TCS with those in deeply virtual Compton scattering. Our estimates, based on a $\pi$-meson GPD model, indicate that these contributions are sizeable and will play a crucial role in the interpretation of data from current and forthcoming experiments.

The hot and dense hadronic medium formed during the heavy-ion collisions at the Relativistic Heavy Ion Collider and Large Hadron Collider energies can show thermoelectric effects in the presence of temperature gradients and nonzero baryon chemical potential. In this article, we study the thermoelectric coefficients of an interacting hot and dense hadron gas using the relativistic Boltzmann transport equation under the relaxation time approximation. We discuss the thermoelectric properties within different frameworks of hadron resonance gas models. In the presence of an external magnetic field, the thermoelectric coefficients become anisotropic, which leads to Hall-like thermoelectric coefficients, namely Nernst coefficients, along with the magneto-Seebeck coefficients. For the first time, we also estimate the Thomson coefficient of the medium, which comes into the picture due to the temperature dependence of the Seebeck coefficient of the medium. In the context of studying the thermoelectric generator performance, we calculate the values of the thermoelectric figure of merit of the medium.

Masses of the singly heavy baryons (SHBs), composed of a heavy quark and a light diquark, are studied from the viewpoints of heavy-quark spin symmetry (HQSS) and chiral-symmetry restoration at finite temperature. We consider the light diquarks with spin-parity $J^P=0^{\pm }$ and $1^{\pm }$. Medium corrections to the SHBs are provided through the diquarks whereas the heavy quark is simply regarded as a spectator. The chiral dynamics of the diquark are described by the Nambu-Jona-Lasinio (NJL) model having (pseudo)scalar-type and (axial)vector-type four-point interactions and the six-point ones responsible for the $U(1)$ axial anomaly. The divergences are handled by means of the three-dimensional proper-time regularization with both ultraviolet and infrared cutoffs included, in order to eliminate unphysical imaginary parts. As a result, the mass degeneracies between the parity partners of all the SHBs are predicted in accordance with the chiral restoration. In particular, the HQS-doublet SHBs exhibit clear mass degeneracies due to the absence of the direct anomaly effects. We also predict a mass degeneracy of ${\mathrm{\Sigma }}_c$ and ${\mathrm{\Omega }}_c$ above the pseudocritical temperature $T_{\mathrm{pc}}$ of chiral restoration, which results in a peculiar mass hierarchy for positive-parity HQS-doublet SHBs where ${\mathrm{\Xi }}_c^{\prime }$ becomes heavier than ${\mathrm{\Omega }}_c$ Besides, it is found that the decay width of ${\mathrm{\Sigma }}_c\to {\mathrm{\Lambda }}_c\pi$ vanishes above $T_{\mathrm{pc}}$ reflecting a closing of the threshold. The predicted modifications of masses and decay widths of the SHBs are expected to provide future heavy-ion collision experiments and lattice simulations with useful information on chiral dynamics of the diquarks.

The Electron-Ion Collider (EIC) is an upcoming accelerator facility aimed at exploring the properties of quarks and gluons in nucleons and nuclei, shedding light on their structure and dynamics. The inaugural experimental apparatus, ePIC (electron-Proton and Ion Collider), is designed as a general-purpose detector to address the National Academy of Sciences and the Nuclear Science Advisory Committee physics program at the EIC. The wider EIC community is strongly supporting a second interaction region and an associated second detector to enhance the full science program. In this study, we evaluate how this second interaction region and detector can be complementary to ePIC. The layout of an interaction region for the second detector offers a secondary focus that provides better forward detector acceptance at scattering angles near $\theta \sim 0\mathrm{mrad}$, which can specifically enhance the exclusive, tagging, and diffractive physics program. This article presents an analysis of a tagging program using the second interaction region layout with incoherent diffractive vector meson production. The current design of the second EIC interaction region is evaluated for its vetoing capabilities of incoherent events required for the study of coherent diffractive measurements. We find an increased vetoing performance compared to the ePIC interaction region, thus improving measurements which are important for the spatial imaging of nucleons and nuclei.

We explore the consequence of generalized symmetries in four-dimensional $\mathcal{N}=1$ superconformal field theories. First, we classify all possible supersymmetric gauge theories with a simple gauge group that have a nontrivial one-form symmetry and flows to a superconformal field theory. Upon identifying unbroken discrete zero-form symmetries from the Adler-Bell-Jackiw (ABJ) anomaly, we find that many of these theories have mixed zero-form or one-form ’t Hooft anomalies. Then we classify the relevant deformations of these SCFTs that preserve the anomaly. From this mixed anomaly together with the anomalies of the discrete zero-form symmetries, we find obstructions for the relevant deformations of these SCFTs to flow to a trivially gapped phase. We also study non-Lagrangian SCFTs formed by gauging copies of Argyres-Douglas theories and constrain their deformations. In particular, we explore a new duality between the diagonal gauging of two ${\mathcal{D}}_3(SU(N))$ theories and $SU(N)$ gauge theory with two adjoints. We also repeat our analysis for a host of nonsupersymmetric gauge theories having nontrivial one-form symmetry including examples that appear to flow to Bank-Zaks type CFTs.

Gravitational lensing of gravitational waves (GWs) provides a unique opportunity to study cosmology and astrophysics at multiple scales. Detecting microlensing signatures, in particular, requires efficient parameter estimation methods due to the high computational cost of traditional Bayesian inference. In this paper we explore the use of deep learning, namely conditional variational autoencoders (CVAE), to estimate parameters of microlensed binary black hole (simulated) waveforms. We find that our CVAE model yields accurate parameter estimation and significant computational savings compared to Bayesian methods such as bilby (up to five orders of magnitude faster inferences). Moreover, the incorporation of CVAE-generated priors into bilby, based on the 95% confidence intervals of the CVAE posterior for the lensing parameters, reduces bilby’s average runtime by around 48% without any penalty on accuracy. Our results suggest that a CVAE model is a promising tool for future low-latency searches of lensed signals. Further applications to actual signals and integration with advanced pipelines could help extend the capabilities of GW observatories in detecting microlensing events.

In this study, we investigate the inspiral dynamics of a stellar-mass object around a central black hole (BH) incorporating loop quantum gravity (LQG) effects. The BH spacetime is characterized by an LQG correction parameter $r_0$, which quantifies deviations from the classical Schwarzschild geometry. Our analysis reveals that LQG effects accelerate the orbital decay compared to the Schwarzschild scenario. Furthermore, we employ the fastemriwaveforms (few) package to generate gravitational waveforms and assess the Laser Interferometer Space Antenna’s capability to detect the LQG effect with faithfulness and the Fisher information matrix method. These results highlight the potential of space-based gravitational wave detectors to probe quantum gravity effects in astrophysical environments.