Several astrophysical and cosmological observations suggest the existence of dark matter (DM) through its gravitational effects, yet its nature remains elusive. Despite the lack of DM signals from direct detection experiments, efforts continue to focus on the indirect detection of DM from DM-rich astrophysical objects. Dwarf spheroidal galaxies (dSphs) are among the most promising targets for such searches. In this work, we aim to investigate the expected DM capture rate from the stellar component of ten nearby DM-rich dSphs, assuming that the accumulated DM eventually annihilates into light, long-lived mediators (LLLMs) which decay into gamma rays outside the dSphs. We analyze nearly 16 years of Fermi-LAT data to search for DM annihilation through LLLMs, and, from the observed stacked flux upper limits, set limits on the DM-nucleon scattering cross section for the case of a generic DM scenario. Additionally, we incorporate the Sommerfeld enhancement (SE) effect into the DM annihilation process assuming a scalar DM model, and obtain bounds on the DM-nucleon scattering cross section of $\sim {10}^{-36}{\mathrm{cm}}^2$ for DM masses around 100 GeV. This allows us to explore an alternative avenue for exploring DM phenomena from dSphs and compare our results with the bounds reported by direct DM detection experiments and other celestial bodies.

Neutrino propagation in the Galactic and extragalactic magnetic fields is considered. We extend an approach developed in [A. Popov and A. Studenikin, Neutrino eigenstates and flavour, spin and spin-flavour oscillations in a constant magnetic field, Eur. Phys. J. C 79, 144 (2019).] to describe neutrino flavor and spin oscillations using wave packets. The evolution equations for the neutrino wave packets in a uniform and nonuniform magnetic fields are derived. The analytical expressions for neutrino flavor and spin oscillations probabilities accounting for damping due to the wave packet separation are obtained for the case of a uniform magnetic field. It is shown that terms in the flavor oscillations probabilities that depend on the magnetic field strength are characterized by two coherence lengths. One of the coherence lengths coincides with the coherence length for neutrino oscillations in vacuum, while the second one is proportional to the cube of the average neutrino momentum $p_0^3$. The probabilities of flavor and spin oscillations are calculated numerically for neutrino interacting with the nonuniform Galactic magnetic field. It is shown that oscillations on certain frequencies are suppressed on the Galactic scale due to the neutrino wave packets separation. The flavor compositions of high-energy neutrino flux coming from the Galactic center and ultra-high energy neutrinos from an extragalactic source are calculated accounting for neutrino interaction with the magnetic field and decoherence due to the wave packet separation. It is shown that for neutrino magnetic moments $\sim {10}^{-13}{\mu }_B$ and larger these flavor compositions significantly differ from ones predicted by the vacuum neutrino oscillations scenario.

The low-energy, finite-volume spectrum of the two-nucleon system at a quark mass corresponding to a pion mass of $m_{\pi }\approx 806\mathrm{MeV}$ is studied with lattice quantum chromodynamics (LQCD) using variational methods. The interpolating-operator sets used in [Variational study of two-nucleon systems with lattice QCD, Phys. Rev. D 107, 094508 (2023).] are extended by including a complete basis of local hexaquark operators, as well as plane-wave dibaryon operators built from products of both positive- and negative-parity nucleon operators. Results are presented for the isosinglet and isotriplet two-nucleon channels. In both channels, noticeably weaker variational bounds on the lowest few energy eigenvalues are obtained from operator sets which contain only hexaquark operators or operators constructed from the product of two negative-parity nucleons, while other operator sets produce low-energy variational bounds which are consistent within statistical uncertainties. The consequences of these studies for the LQCD understanding of the two-nucleon spectrum are investigated.

As a complement to conventional perturbative quantum chromodynamics (pQCD) there is an approach that is called covariant parton model (CPM). As mentioned in related literature, this model is based on the intrinsic motion of quarks where a spherical symmetry is assumed for distribution of fermion momenta in three dimensions inside the nucleon. This model provides the exact spin value for the nucleon by assuming it contains only three valence quarks. This model also gives accurate numerical results for various QCD sum rules. Hence, it would be advantageous to analyze the spin structure functions of a nucleon in CPM. For this purpose we resort to the solution of the Dirac equation with a harmonic oscillator potential to yield us the bare quark densities. Following that utilizing the chiral quark model, the $u_v$ and $d_v$ valence quark densities can be determined at an initial energy scale. By achieving the required input and doing the evolution of valence densities, $g_1$ and $g_2$ spin nucleon structure functions can be extracted in CPM, demonstrating qualitative agreement with experimental findings. We also compute these structure functions through conventional pQCD at next-to-leading-order accuracy, which, in addition to the evolution of valence densities, necessitates the evolution of sea and gluon densities. The findings are similar to those from CPM, suggesting the effectiveness of CPM for conducting phenomenological analyses.

We investigate an analog model of charged black hole (BH) formation using the framework of classical percolation. By analyzing the scaling behavior of key quantities, including surface gravity and Komar mass, we establish a robust correspondence between this analog system and gravitational collapse in general relativity. Our numerical simulations of the lattice model show excellent agreement with analytical predictions for the continuum limit, highlighting the potential of analog systems to capture essential features of BH physics. Interestingly, we find that while geometric criteria related to the hoop conjecture are necessary, they are not sufficient for BH formation in our model. Instead, the exponential growth of energy and cluster size emerges as the key indicator, suggesting a novel interpretation of the hoop conjecture and providing further support for cosmic censorship within our analog framework by ensuring horizon formation. This work offers a fresh perspective on the organization of matter within BH event horizons and lays the groundwork for future quantum extensions that could shed light on Hawking radiation and the BH information paradox by linking entanglement entropy in quantum percolation models to BH entropy.

We demonstrate that the liquid gas transition of nuclear matter can be rigorously described with the quantum chromodynamics by combining the quark gap equation and the Faddeev equation of nucleon. Our investigation focuses on this transition at zero temperature and finite chemical potential, revealing a finite difference between the gas and liquid solution of the quark propagator. This difference emerges from the shift of the nucleon pole mass in medium, which is generated in the nucleon channel of the quark gap equation. We prove that such a difference is precisely the contour contribution from the shift of the nucleon pole. The resulting discontinuity manifests as a first-order phase transition and fundamentally determines both the nuclear binding energy and the saturation density. We then derive an analytical relation between the binding energy and the sigma term of the nucleon, yielding a binding energy of $E/A=15.9\mathrm{MeV}$. Furthermore, by establishing the relation between the nuclear saturation density and the vector charge of nucleon in association with the binding energy, we determine the saturation density to be $n_{\mathrm{B}}^0=0.15{\mathrm{fm}}^{-3}$.

Recently, two types of solutions to the long-standing issue of general covariance in canonical quantum gravity have been proposed. From the above, a fundamental question arises: which solution is superior? Considering one type of solution with a Cauchy horizon, in the present paper, we explore whether it exhibits properties similar to those of the Reissner-Nordström black hole. Due to its geometric similarity, application of the generalized Dray-’t Hooft-Redmond relation reveals evidence of mass inflation, indicating that the Cauchy horizon is unstable. While this is consistent with the strong cosmic censorship conjecture, it suggests that it does not represent a regular black hole. Furthermore, we extend the metric to include a cosmological constant and study the validity of the strong cosmic censorship conjecture for the quantum black hole in de Sitter spacetime. After taking into account the reasonable ranges of parameters for the quantum black hole, we find that the strong cosmic censorship conjecture holds.

We construct a new dilaton Weyl multiplet for $\mathcal{N}=3$ conformal supergravity in four dimensions. The R-symmetry realized on this dilaton Weyl multiplet is $SU(2)\times U(1)\times U(1)$. The construction follows a two-step procedure. First, two on-shell vector multiplets are coupled to the standard Weyl multiplet. Second, using the field equations of the vector multiplets, some of the auxiliary fields of the standard Weyl multiplet are solved in terms of the fields belonging to the vector multiplets and some dual gauge fields. The remaining fields of the standard Weyl multiplet combine with the vector multiplet fields and the dual gauge fields to constitute the new dilaton Weyl multiplet.

Gaussian quantum mechanics is a powerful tool regularly used in quantum optics to model linear and quadratic Hamiltonians efficiently. Recent interest in qubit–continuous-variable (CV) hybrid models has revealed a simple, yet important gap in our knowledge, namely, how to fully manipulate superpositions of Gaussian states. In this paper, we show how to faithfully represent a quadratic Gaussian state in the Fock basis. Specifically, we evaluate the phase necessary to equate the unitary representation of a zero-mean Gaussian state with its Fock representation. This allows for the coherent manipulation of superpositions of Gaussian states, especially the evaluation of expectation values from these superposed states. We then use this method to model a simple quantum field theory communication protocol using quadratic detectors in a regime that has previously been impossible to solve. The result presented in this paper is expected to become increasingly relevant with hybrid-CV systems, especially in the strong-coupling regime.

We investigate an Otto thermodynamic cycle with a qubit Unruh-DeWitt detector as the working medium, coupled to a massless, conformally coupled scalar quantum field in the Hartle-Hawking vacuum in a ($2+1$)-dimensional BTZ black hole spacetime. We employ the thermal properties of the field to model heat and cold reservoirs between which the thermal machine operates. Treating the detector as an open quantum system, we employ a master equation to study its finite-time dynamics during each cycle stroke. We evaluate the output performance of the Otto heat engine and refrigerator by computing, respectively, the total work output and the cooling power for each of the Neumann, transparent, and Dirichlet boundary condition cases satisfied by the field at spatial infinity. Furthermore, we evaluate the optimal performance of the thermal machine by analyzing its efficiency at maximum power output and ecological impact. Our study presents a general framework for understanding the finite-time operation of relativistic quantum thermal machines, focusing on their energy optimization.

In this paper we study the effect of localizing quantum field degrees of freedom by dynamically growing cavity walls through a time-dependent potential. We use our results to show that it is possible to do this without introducing non-negligible mixedness in localized modes of the field. We discuss how this addresses the concerns, raised in previous literature, that the high degree of entanglement of regular states in QFT may hinder relativistic quantum information protocols that make use of localized relativistic probes.

We consider the vacuum wave function of a free scalar field theory in space partitioned into two regions, with the field obeying Robin conditions (of parameter $\kappa$) on the interface. A direct integration over fields in a subregion is carried out to obtain the reduced density matrix. This leads to a constructive proof of the Reeh-Schlieder theorem. We analyze the entanglement entropy as a function of the Robin parameter $\kappa$. We also consider a specific conditional probability as another measure of entanglement which is more amenable to analysis of the dependence on interface conditions. Finally, we discuss a direct calculation of correlation functions and how it gives an alternate route to the reduced density matrix.

In the plane wave spacetime, when gravitational waves pass by, an angular deviation exists between two free-falling gyroscopes, which naturally corresponds to the velocity variation. In the plane wave spacetime, with linear polarization taken into account, no contribution is made by the first-order terms of the initial separation distance $L$ (or the initial separation velocity $v_0$) and $\mathit{P}$ (or $\mathit{M}$) of two free-falling gyroscopes to the memory effect, while contributions are initiated from the second-order terms. Under certain circumstances, the second-order contribution of the initial separation distance $L$ is of the same order of magnitude as the first-order contribution of the initial separation velocity $v_0$. When $\mathrm{both}+\text{polarization}$ and $\times$ polarization are taken into account, in the context of the merger of supermassive black holes and with the initial separation velocity approaching the speed of light, the order of magnitude of the angle is ${10}^{-16}\mathrm{rad}$.

We use a hybrid effective field theory (HEFT) model to constrain the evolution of low-redshift ($z\lesssim 0.4$) matter fluctuations by cross-correlating DESI Bright Galaxy Survey (BGS) legacy imaging with the latest cosmic microwave background (CMB) lensing maps from Planck and Atacama cosmology telescope. Our tomographic BGS analysis finds that the evolution and amplitude of matter fluctuations align with CMB-conditioned $\mathrm{\Lambda }$ cold dark matter predictions. When including DESI baryon acoustic oscillation (BAO) measurements we obtain ${\sigma }_8={0.876}_{-0.067}^{+0.051}$ from BGS alone. Jointly analyzing BGS and luminous red galaxy (LRG) cross-correlations with the same CMB lensing maps yields ${\sigma }_8=0.791\pm 0.021$. As a complementary approach we isolate the galaxy magnification signal from the cross-correlation of nonoverlapping BGS and LRG photometric redshift bins, ruling out the null-magnification hypothesis at $11\sigma$. For the first time, we constrain quasilinear structure growth from the (finite-difference calibrated) galaxy magnification signal and find ${\sigma }_8=0.720\pm 0.047(\mathrm{stat})\pm 0.050(\mathrm{sys})$ assuming a linear bias model and including BAO data.

Wave-optics phenomena in gravitational lensing occur when the signal’s wavelength is commensurate to the gravitational radius of the lens. Although potentially detectable in lensed gravitational waves, fast radio bursts and pulsars, accurate numerical predictions are challenging to compute. Here we present novel methods for wave-optics lensing that allow the treatment of general lenses. In addition to a general algorithm, specialized methods optimize symmetric lenses (arbitrary number of images) and generic lenses in the single-image regime. We also develop approximations for simple lenses (point-like and singular isothermal sphere) that drastically outperform known solutions without compromising accuracy. These algorithms are implemented in Gravitational Lensing of Waves (glow); an accurate, flexible, and fast code. glow efficiently computes the frequency-dependent amplification factor for generic lens models and arbitrary impact parameters in $\mathcal{O}(1\mathrm{ms})$ to $\mathcal{O}(10\mathrm{ms})$ depending on the lens configuration and complexity. glow is readily applicable to model lensing diffraction on gravitational-wave signals, offering new means to investigate the distribution of dark-matter and large-scale structure with signals from ground and space detectors.

We study the formation and the dynamics of vortex lines in rotating scalar dark matter halos, focusing on models with quartic repulsive self-interactions. In the nonrelativistic regime, vortex lines and their lattices arise from the Gross-Pitaevskii equation of motion, as for superfluids and Bose-Einstein condensates studied in laboratory experiments. Indeed, in such systems, vorticity is supported by the singularities of the phase of the scalar field, which leads to a discrete set of quantized vortices amid a curl-free velocity background. In the continuum limit where the number of vortex lines becomes very large, we find that the equilibrium solution is a rotating soliton that obeys a solid-body rotation, with an oblate density profile aligned with the direction of the total spin. This configuration is dynamically stable provided the rotational energy is smaller than the self-interaction and gravitational energies. Using numerical simulations in the Thomas-Fermi regime, with stochastic initial conditions for a spherical halo with a specific averaged density profile and angular momentum, we find that a rotating soliton always emerges dynamically, within a few dynamical times, and that a network of vortex lines aligned with the total spin fills its oblate profile. These vertical vortex lines form a regular lattice in the equatorial plane, in agreement with the analytical predictions of uniform vortex density and solid-body rotation. These vortex lines might further extend between halos to form the backbone of spinning cosmic filaments.

Collective neutrino flavor oscillations are of primary importance in understanding the dynamic evolution of core-collapse supernovae and subsequent terrestrial detection, but also among the most challenging aspects of numerical simulations. This situation is complicated by the quantum many-body nature of the problem due to neutrino-neutrino interactions, which demands a quantum treatment. An additional complication is the presence of three flavors, which often is approximated by the electron flavor and a heavy lepton flavor. In this work, we provide both qubit and qutrit encodings for all three flavors, and develop optimized quantum circuits for the time evolution and analyze the Trotter error. We conclude our study with a hardware experiment of a system of two neutrinos with superconducting hardware: the IBM Torino device for qubits and Advanced Quantum Testbed device at the Lawrence Berkeley National Laboratory for qutrits. We find that error mitigation greatly helps in obtaining a signal consistent with simulations. While hardware results are comparable at this stage, we expect the qutrit setup to be more convenient for large-scale simulations since it does not suffer from probability leakage into nonphsycial qubit space, unlike the qubit setup.

A conditional variational autoencoder (CVAE) model is employed for parameter inference on gravitational waves (GW) signals of massive black hole binaries, considering joint observations with a network of three space-based GW detectors. Our experiments show that the trained CVAE model can estimate the posterior distribution of source parameters in approximately one second, while the standard Bayesian sampling method, utilizing parallel computation across 16 CPU cores, takes an average of 20 hours for a GW signal instance. However, the sampling distributions from CVAE exhibit lighter tails, appearing broader when compared to the standard Bayesian sampling results. By using CVAE results to constrain the prior range for Bayesian sampling, the sampling time is reduced by a factor of $\sim 6$ while maintaining the similar precision of the Bayesian results.

More than a decade ago, the IceCube Neutrino Observatory discovered a diffuse flux of 10 TeV–10 PeV neutrinos from our Universe. This flux of unknown origin most likely emanates from an extragalactic population of neutrino sources, which are individually too faint to appear as bright emitters. We review constraints on extragalactic neutrino source populations based on the nondetection of the brightest neutrino source. Extending previous work, we discuss limitations of source populations based on general neutrino luminosity functions. Our method provides more conservative but also statistically more robust predictions for the expected number of observable sources. We also show that the combined search of the brightest neutrino sources via weighted stacking searches or the analysis of non-Poissonian fluctuations in event-count histograms can improve the discovery potential by a factor of 2–3 relative to the brightest source.

The force acting on a proton vortex in extreme type-II superconducting neutron star matter is studied in the limit of vanishing temperature. A detailed analysis is presented on how momentum is transferred from length scales on the order of the London penetration depth to the vortex core. To examine the momentum flux, expressions for proton and electron currents are derived for arbitrary distances from the vortex line. It is shown that, in the regime of a large electron mean free path, the only force acting directly on the vortex core is the Magnus force. Notably, the correction to the proton current near the vortex core generates a component of the Magnus force aligned with the incident current measured far from the vortex. This contribution, responsible for longitudinal force, is usually overlooked in the literature. The results obtained in this work for a relatively simple problem concerning the force on a vortex in cold matter of neutron stars may also be relevant to other superconducting systems.