Accurate modeling of the one-to-two halo transition has long been difficult to achieve. We demonstrate that physically motivated halo definitions that respect the bimodal phase-space distribution of dark matter particles near halos resolves this difficulty. Specifically, the two phase-space components are overlapping and correspond to (1) particles orbiting the halo and (2) particles infalling into the halo for the first time. Motivated by this decomposition, García et al. [Mon. Not. R. Astron. Soc. 521, 2464 (2023)] advocated for defining halos as the collection of particles orbiting their self-generated potential. This definition identifies the traditional one-halo term of the halo-mass correlation function with the distribution of orbiting particles around a halo, while the two-halo term governs the distribution of infalling particles. We use dark matter simulations to demonstrate that the distribution of orbiting particles is finite and can be characterized by a single physical scale $r_{\mathrm{h}}$, which we refer to as the halo radius. The two-halo term is described using a simple yet accurate empirical model based on the Zel’dovich correlation function. We further demonstrate that the halo radius imprints itself on the distribution of infalling particles at small scales. Our final model for the halo-mass correlation function is accurate at the $\approx 2\%$ level for $r\in [0.1,50]h^{-1}\mathrm{Mpc}$. The Fourier transform of our best-fit model describes the halo-mass power spectrum with comparable accuracy for $k\in [0.06,6.0]h{\mathrm{Mpc}}^{-1}$.

After neutrinos decouple from the photon bath, they can populate a thermal dark sector. If this neutrino cooling occurs at a temperature above $\sim 100\mathrm{keV}$, it can impact light element abundances. We calculate the changes to the ${\mathrm{Y}}_{\mathrm{P}}$ and $\mathrm{D}/\mathrm{H}$ abundances in this scenario with a suitably customized version of the public big bang nucleosynthesis code PRIMAT. If electron neutrinos significantly participate in the cooling, we find limits down to temperatures as low as 100 keV. And if the dark sector undergoes a “step” in $N_{\mathrm{eff}}$, there can be additional, ${\omega }_b$-dependent constraints.

Scale-independent energy-momentum squared gravity (EMSG) allows different gravitational couplings for different types of sources and has been proven to have interesting implications in cosmology. In this paper, the big bang nucleosynthesis (BBN) formalism and the latest observational constraints on nuclear abundances are being used to put bounds on this class of modified gravity models. Using the tight constraint from BBN on the correction term in the Friedmann equation in EMSG scenario, we report the allowed deviation from the standard cosmic expansion rate.

Untangling the connection between redshift space coordinates, a velocity measurement, and three dimensional real space coordinates is a cosmological problem that is often modeled through a linear understanding of the velocity-position coupling. This linear information is better preserved in the Lagrangian space picture of the matter density field. Through Lagrangian space measurements, we can extract more information and make more accurate estimates of the linear growth rate of the Universe. In this paper, we address the linear modeling of matter particle velocities through transfer functions, and in doing so examine to what degree the decrease in correlation with initial conditions may be contaminated by velocity-based nonlinearities. With a thorough analysis of the monopole-quadrupole ratio, we find the best-fitting values for the Eulerian velocity dispersion, ${\sigma }_p=378.3\mathrm{km}/\mathrm{s}$ for a Lorentzian finger-of-God damping factor and ${\sigma }_p=254.6\mathrm{km}/\mathrm{s}$ for a Gaussian one. The covariance of the cosmological linear growth rate $f$ is estimated in the Eulerian and Lagrangian cases. Comparing Lagrangian and Eulerian, we find that the error in $f$ improves by a factor of 3, without the need for nonlinear velocity dispersion modeling.

At sufficiently low nuclear recoil energy, the scattering of dark matter (DM) in crystals gives rise to single phonon and multiphonon excitations. In anisotropic crystals, the scattering rate into phonons modulates over each sidereal day as the crystal rotates with respect to the DM wind. This gives a potential avenue for directional detection of DM. The daily modulation for single phonons has previously been calculated. Here we calculate the daily modulation for multiphonon excitations from DM in the mass range 1 MeV–1 GeV. We generalize previous multiphonon calculations, which made an isotropic approximation, and implement results in the DarkELF package. We find daily modulation rates up to 1%–10% for an ${\mathrm{Al}}_2{\mathrm{O}}_3$ target and DM mass below 30 MeV, depending on the recoil energies probed. We obtain similar results for SiC, while modulation in Si, GaAs, and ${\mathrm{SiO}}_2$ is negligible.

The abundance of massive primordial black holes has historically been constrained by dynamical probes. Since these objects can participate in hard few-body scattering processes, they can readily transfer energy to stellar systems and, in particular, disrupt wide binaries. However, disruption is not the only possible outcome of such few-body processes. Primordial black holes could also participate in exchange processes, in which one component of a binary system is ejected and replaced by the black hole itself. In this case, the remaining object in the binary would dynamically appear to have an invisible companion. We study the rate of exchange processes for primordial black holes as a component of dark matter and evaluate possible mechanisms for detecting such binaries. We find that many such binaries plausibly exist in the Solar neighborhood and show that this process can account for observed binary systems whose properties run counter to the predictions of isolated binary evolution.

This study aims to detect and characterize quasiperiodic oscillations (QPOs) signals in x-ray observations of NGC 4151. We employed the weighted wavelet Z-transform and Lomb-Scargle periodogram methods for our analysis. QPO signals with frequencies of $5.91\times {10}^{-4}\mathrm{Hz}$ and $5.68\times {10}^{-4}\mathrm{Hz}$ were detected in observations conducted by Chandra (ObsID 7830) in 2007 and XMM-Newton (ObsID 0761670301) in 2015, with confidence levels of $3.7\sigma$ and $3.3\sigma$, respectively. These signals are the first to be independently observed by two different telescopes over an eight-year period with closely matched frequencies. Most notably, the combined confidence level of the QPO signals from these two independent observations reaches an exceptional $5.2\sigma$, which is rare in astrophysical research and significantly strengthens our conviction in the authenticity of these signals. A detailed analysis of the observational data suggests that these QPO signals may be correlated with the properties of the central supermassive black hole. Additionally, spectral analysis of the observational data revealed no significant spectral differences between the QPO and non-QPO segments. These findings provide new insights into the x-ray variability mechanisms of the central black hole in NGC 4151 and offer a novel perspective for black hole mass estimation.

Axionlike particles (ALPs), hypothetical particles, are known to be produced through axion-photon conversion in the presence of a stationary external magnetic field that is strong enough. Devices such as undulators and wigglers, which are used widely for photon production, e.g., in synchrotron radiation facilities, inherently possess strong magnetic fields, making them potential sources for ALP production without introducing additional light source or magnetic fields. In this paper, we establish formalisms and formulas for studying ALP production in the ALP-photon-charged current system based on quantum field theory. We demonstrate that ALP production is inevitable in any undulator with the standard designs due to the electron Coulomb potential as well as a “photon resonance” effect depending on the ALP mass. In particular, ALPs are predominantly produced in a direction slightly misaligned with the photons’ main direction. We propose placing detectors in the desired directions during operations of the originally planned experiments as an efficient approach to simultaneously probing ALPs. The calculation methods and formulas developed in this study are applicable to ALP production from other environments and productions of other particles beyond the standard model relevant to synchrotron radiations.

We investigate the existence of Bogomol’nyi-Prasad-Sommerfield (BPS) structures in Maxwell-Higgs electrodynamics immersed in a chiral medium. The medium has its electromagnetic properties controlled by both a Chern-Simons term and a neutral scalar field. We implement the Bogomol’nyi-Prasad-Sommerfield technique and minimize the corresponding total energy. As a consequence, we get the BPS potential and the self-dual equations whose solutions saturate the Bogomol’nyi bound. In such a context, we look for vortices in two chiral media. The first one engenders localized configurations with an exponential decay similar to that of the standard Abrikosov-Nielsen-Olesen solutions. The second medium generates delocalized profiles whose tail follows a power-law decay. In both cases, we discuss the effects on the shape of the field profiles due to the chiral medium.

We report a study of the determination of the intrinsic transverse momentum of partons, the intrinsic $k_T$, from the dilepton transverse momentum $p_T$ in Drell-Yan (DY) production at hadron colliders. The result shows that a good sensitivity to the intrinsic $k_T$ distribution is achieved by measuring relative ratios between the cross sections of suitably defined low-$p_T$ and high-$p_T$ regions. The study is performed through both a pseudodata test and an extraction from measurements of the DY process by the CMS Collaboration. Since the methodology does not rely on any dedicated partition of bins, this $p_T$-ratio observable requires less special treatment in very low $p_T$ regions and propagates lower systematic uncertainties induced from unfolding or momentum migration, in contrast with previous proposals of using a fine-binning measurement of the differential cross section.

We argue that the long-standing issues of neutrino mass and dark matter can be manifestly solved in a dark gauge symmetry $U(1{)}_D$ that transforms nontrivially only for three right-handed neutrinos ${\nu }_{1,2,3R}$—the counterparts of known left-handed neutrinos. This theory assigns the ${\nu }_{1,2,3R}$ dark charge to be $D=0$, $-1$, and $+1$, respectively, in order for anomaly cancelation. Additionally, it imposes an inert Higgs doublet $\eta$ and two Higgs singlets $\xi ,\varphi$ with dark charge $D=+1$, $-1$, and $+2$, respectively. That said, the dark symmetry is broken by $\varphi$ (by two units) down to a dark parity $P_D=(-1{)}^D$, for which ${\nu }_{2,3R}$ and $\eta$, $\xi$ are odd, whereas all other fields are even due to $D=0$. The lightest of these odd fields is stabilized by $P_D$, which is responsible for dark matter. Neutrino masses are generated by a scotoseesaw scheme, in which the seesaw part is mediated by ${\nu }_{1R}$, while the scotogenic part is mediated by ${\nu }_{2,3R}$, for which the hierarchy of atmospheric and solar neutrino mass splittings is explained.

We investigate high and low energy implications of a gauge dual description of the Standard Model. The high energy electric theory features gauge dynamics involving only fermionic matter fields, while the low energy magnetic description features a quasisupersymmetric spectrum testable at colliders. The flavor theory is constructed via operators generated at the Planck scale, possibly by gravitational global symmetry breaking interactions. We further show that duality opens novel avenues for theories of grand unification.

We study the potential of a set of future detectors, proposed to be located at the European Spallation Source (ESS), to probe neutrino millicharges through coherent elastic neutrino-nucleus scattering. In particular, we focus on detectors with similar characteristics as those that are under development for operation at the ESS, including detection technologies based on cesium iodine, germanium, and noble gases. Under the considered conditions, we show that the Ge detector, with a lighter nuclear target mass with respect to CsI and a noble gas like Xe, is more efficient to constrain neutrino millicharges, reaching a sensitivity of $\sim {10}^{-9}e$ for diagonal neutrino millicharges, and $\sim {10}^{-8}e$ for the transition ones. In addition, we study the effects of including electron scattering processes for the CsI detector, achieving an expected sensitivity of $\sim {10}^{-11}e$ for the diagonal millicharges.

In the literature, the neutrino $\mu -\tau$ reflection symmetry (which has the interesting predictions ${\theta }_{23}=\pi /4$ and $\delta =\pm \pi /2$ for the atmospherical neutrino mixing angle and Dirac $CP$ phase) is an attractive and widely studied candidate for the flavor symmetries in the neutrino sector. However, it is known that, when the seesaw model is furnished with this symmetry, the leptogenesis mechanism (which provides an elegant explanation for the baryon-antibaryon asymmetry of the Universe) can only work in the two-flavor regime (which only holds for the right-handed neutrino masses in the range ${10}^9–{10}^{12}\mathrm{GeV}$). This prohibits us to have a low scale seesaw model (which has the potential to be directly accessed by running or upcoming collider experiments) that can have the $\mu -\tau$ reflection symmetry and successful leptogenesis simultaneously. In this paper, for the first time, we demonstrate that the successful leptogenesis may also be achieved in low scale seesaw models furnished with the $\mu -\tau$ reflection symmetry, by means of the flavor nonuniversality of the conversion efficiencies from the flavored lepton asymmetries to the baryon asymmetry via the sphaleron process. We perform the study in both the resonant leptogenesis regime and the leptogenesis via oscillations (Akhmedov-Rubakov-Smirnov leptogenesis) regime.

Axionlike particles (ALPs) can be produced in meson decays via tree-level quark-flavor-violating couplings, and decay to a pair of sterile neutrinos if also coupled to them. Such light sterile neutrinos are necessarily long-lived and may give rise to striking signatures of displaced vertices (DVs) at terrestrial experiments. In this work, we study the prospect of the ongoing Belle II experiment for detecting the sterile neutrinos from the ALP, leveraging the $\mathcal{O}({10}^{10})$ $B$-mesons projected to be produced at the experiment with an integrated luminosity of $50{\mathrm{ab}}^{-1}$. We propose search strategies for one or two DVs, and perform Monte-Carlo simulations in order to estimate the sensitivity reach of Belle II to active-sterile-neutrino mixing $|V_{eN}{|}^2$ as functions of the sterile-neutrino mass. Signatures include a selected list of sterile-neutrino final states, for which we estimate an $\mathcal{O}(1)$ or lower background level. Our results show that the proposed search strategies can probe values of $|V_{eN}{|}^2$ up to about two orders of magnitude beyond the existing bounds, for ALP mass over 4 GeV and sterile-neutrino mass above the $D$-meson threshold. Compared to the one-DV search, the two-DV one, despite its weaker sensitivities as a result of double exponential suppression of the sterile-neutrino decay positions, possesses the advantage of possible full reconstruction of the signal event allowing for pinning down the masses of the sterile neutrino and the ALP, if a discovery is made.

A key issue affecting the attempt to reduce the uncertainty on the Standard Model prediction for the muon anomalous magnetic moment is the current discrepancy between lattice-QCD and data-driven results for the hadronic vacuum polarization. Progress on this issue benefits from precise data-driven determinations of the isospin-limit light-quark-connected (lqc) and strange-plus-light-quark-disconnected ($\mathrm{s}+\mathrm{lqd}$) components of the related RBC/UKQCD windows. In this paper, using a strategy employed previously for the intermediate window, we provide data-driven results for the lqc and $\mathrm{s}+\mathrm{lqd}$ components of the short- and long-distance RBC/UKQCD windows. Comparing these results with those from the lattice, we find significant discrepancies in the lqc parts but good agreement for the $\mathrm{s}+\mathrm{lqd}$ components. We also explore the impact of recent CMD-$3e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ cross section results, demonstrating that an upward shift in the $\rho$-peak region of the type seen in the CMD-3 data serves to eliminate the discrepancies for the lqc components without compromising the good agreement between lattice and data-driven $\mathrm{s}+\mathrm{lqd}$ results.

We present recent results in three-flavor chiral perturbation theory at finite isospin ${\mu }_I$ and strangeness ${\mu }_S$ chemical potentials at zero temperature. The tree-level spectrum for the mesons and gauge bosons in the pion-condensed phase is derived. The phase diagram to $\mathcal{O}(p^2)$ in the ${\mu }_I–{\mu }_S$ plane is mapped out with and without electromagnetic effects. The phase diagram consists of a vacuum phase and three Bose-condensed phases with condensates of ${\pi }^{\pm }$, $K^{\pm }$, and $K^0/{\overline{K}}^0$, respectively. Including electromagnetic interactions, the charged Bose-condensed phases become Higgs phases via the Higgs mechanism. We calculate the pressure, energy density, isospin density, and speed of sound in the pion-condensed phase to $\mathcal{O}(p^4)$. The results are compared with recent lattice simulations and the agreement is very good for isospin chemical potentials up to approximately 180 MeV. Moreover, by integrating out the $s$-quark, we show that the thermodynamic quantities can be mapped onto their two-flavor counterparts with renormalized parameters. The breaking of the U(1) symmetry in the Bose-condensed phases gives rise to a Goldstone boson, whose dispersion is linear for small momenta. We use Son’s prescription to construct an effective theory for the Goldstone mode in the pion-condensed phase, which is valid for momenta $p\ll {\mu }_I$. It is shown that its damping rate is of order $p^5$ in the nonrelativistic limit, which is Beliaev’s result for a dilute Bose gas. It is also shown that in the nonrelativistic limit the energy density can be matched onto the classic result by Lee, Huang and Yang (LHY) for a dilute Bose, with an $s$-wave scattering length that includes radiative corrections.

In this paper, we revisit the entanglement wedge representation of ${\mathrm{AdS}}_3$ bulk fields in terms of CFT operator product expansion (OPE) blocks for a general class of blocks. Given a boundary interval and its associated causal diamond, the OPEs involve boundary operators with or without spin, and located either at spacelike or timelike edges of the diamond. Only for a subset of these cases, can the OPE block be dual to a geodesic bulk field. We show that when applied to de Sitter, a suitable combination of Euclidean OPE blocks can represent a dS scalar integrated over the timelike extremal surfaces, which play an important role in defining pseudoentropy. We also work out some simple higher dimensional examples.

We present a new mode-sum prescription for the efficient computation of renormalized expectation values for a massive, charged, quantum scalar field propagating on a curved space-time background. Our method is applicable to any static, spherically symmetric, four-dimensional space-time with a time-independent, background electrostatic potential and can be used to find the renormalized scalar condensate, current and stress-energy tensor. As an explicit example, we present a calculation of these quantities for a charged scalar field in the Hartle-Hawking state on a Reissner-Nordström black hole background.

We study Einstein-Yang-Mills (EYM) black holes in semiclassical gravity by including in the field equations the expectation value of a renormalized energy-momentum tensor in the Polyakov approximation. We solve the field equations and the equations of motion self-consistently. This framework has previously been used to study vacuum solutions, i.e., quantum corrected Schwarzschild black holes. In our system, which contains black hole hair, we find quantum corrected solutions in which the classical horizon disappears and is replaced by a wormhole structure, similarly to what is found in vacuum. We also find quantum corrected solutions in which the classical horizon disappears, but there is no wormhole structure. Our results indicate that the inclusion of black hole hair in semiclassical gravity still leads to the disappearance of classical horizons for nonextremal black holes in static spherically symmetric systems.