Measurements of secondary cosmic microwave background (CMB) anisotropies, such as the Sunyaev-Zel’dovich (SZ) effect, will enable new tests of neutrino and dark sector properties. The kinetic SZ (kSZ) effect is produced by cosmological flows, probing structure growth. Ultralight axions (ULAs) are a well-motivated dark-matter candidate. Here, the impact of ULA dark matter (with mass ${10}^{-27}$ to ${10}^{-23}\mathrm{eV}$) on kSZ observables is determined, applying new analytic expressions for pairwise cluster velocities and Ostriker-Vishniac signatures in structure-suppressing models. For the future CMB Stage 4 and ongoing Dark Energy Spectroscopic Instrument galaxy surveys, the kSZ effect (along with primary anisotropies) will probe ULA fractions ${\eta }_a={\mathrm{\Omega }}_{\text{axion}}/{\mathrm{\Omega }}_{\mathrm{DM}}$ as low as $\sim 5\%$ if $m_a\simeq {10}^{-27}\mathrm{eV}$ (at 95% C.L.), with sensitivity extending up to $m_a\simeq {10}^{-25}\mathrm{eV}$. If reionization and the primary CMB can be adequately modeled, Ostriker-Vishniac measurements could probe values ${\eta }_a\simeq {10}^{-3}$ if ${10}^{-27}\mathrm{eV}\lesssim m_a\lesssim {10}^{-24}\mathrm{eV}$, or ${\eta }_a\simeq 1$ if $m_a\simeq {10}^{-22}\mathrm{eV}$, within the fuzzy dark matter window.

We study the information content of the angle-averaged redshift space galaxy bispectrum. The main novelty of our approach is the use of a systematic tree-level perturbation theory model that includes galaxy bias, IR resummation, and also accounts for nonlinear redshift space distortions, binning, and projection effects. We analyze data from the perturbation theory challenge simulations, whose cumulative volume of $566h^{-3}{\mathrm{Gpc}}^3$ allows for a precise comparison to theoretical predictions. Fitting the power spectrum and bispectrum of our simulated data, and varying all necessary cosmological and nuisance parameters in a consistent Markov chain Monte Carlo analysis, we find that our tree-level bispectrum model is valid up to $k_{\max }=0.08h{\mathrm{Mpc}}^{-1}$ (at $z=0.61$). We also find that inclusion of the bispectrum monopole improves constraints on cosmological parameters by (5–15)% relative to the power spectrum. The improvement is more significant for the quadratic bias parameters of our simulated galaxies, which we also show to deviate from biases of the host dark matter halos at the $\sim 3\sigma$ level. Finally, we adjust the covariance and scale cuts to match the volume of the BOSS survey, and estimate that within the minimal $\mathrm{\Lambda }\mathrm{CDM}$ model the bispectrum data can tighten the constraint on the mass fluctuation amplitude ${\sigma }_8$ by roughly 10%.

We introduce and study a new scheme to construct relativistic observables from postprocessing light cone data. This construction is based on a novel approach, lc-metric, which takes general light cone or snapshot output generated by arbitrary $N$-body simulations or emulations and solves the linearized Einstein equations to determine the spacetime metric on the light cone. We find that this scheme is able to determine the metric to high precision, and subsequently generate accurate mock cosmological observations sensitive to effects such as post-Born lensing and nonlinear integrated Sachs-Wolfe contributions. By comparing to conventional methods in quantifying those general relativistic effects, we show that this scheme is able to accurately construct the lensing convergence signal. We also find that the accuracy of this method in quantifying the integrated Sachs-Wolfe effects in the highly nonlinear regime outperforms conventional methods by an order of magnitude. This scheme opens a new path for exploring and modeling higher-order and nonlinear general relativistic contributions to cosmological observables, including mock observations of gravitational lensing and the moving lens and Rees-Sciama effects.

We revisit the constraints on primordial black holes (PBHs) in the mass range ${10}^{13}\mathrm{g}–{10}^{18}\mathrm{g}$ by comparing the 100 keV–5 GeV gamma-ray background with isotropic flux from PBH Hawking radiation (HR). We investigate three effects that may update the constraints on the PBH abundance; (i) reliably calculating the secondary spectra of HR for energy below 5 GeV, (ii) the contributions to the measured isotropic flux from the Galactic PBH HR and that from annihilation radiation due to evaporated positrons, (iii) inclusion of astrophysical background from gamma-ray sources. The conservative constraint is significantly improved by more than an order of magnitude at $2\times {10}^{16}\mathrm{g}\lesssim M\lesssim {10}^{17}\mathrm{g}$ over the past relevant work, where the effect (ii) is dominant. After further accounting for the astrophysical background, more than a tenfold improvement extends to a much wider mass range ${10}^{15}\mathrm{g}\lesssim M\lesssim 2\times {10}^{17}\mathrm{g}$.

In this work we investigate the combined finite-size and thermomagnetic effects on the properties of neutral mesons in a hot medium, in the context of the Nambu–Jona-Lasinio model. In particular, by using the mean-field approximation and the Schwinger proper time method in a toroidal topology with periodic and antiperiodic conditions, we evaluate the chiral phase transition, the critical coupling, the constituent quark mass and meson observables like the ${\pi }^0$ and $\sigma$ meson masses and pion decay constant under the change of the size, temperature and strength of external magnetic field. The results indicate that the observables are strongly affected by the conjoint effects of relevant variables and also by the periodicity of the boundary conditions chosen, and the net result will depend on the balance of these competing phenomena.

We revisit and extend the calculation of the density matrix and entanglement entropy of a color glass condensate (CGC) by including the leading saturation corrections in the calculation. We show that the density matrix is diagonal in the quasiparticle basis, where it has the Boltzmann form. The quasiparticles in a wide interval of momenta behave as massless two-dimensional bosons with the temperature proportional to the typical semihard scale $T=Q_s/\sqrt{{\alpha }_s{N}_c}$. Thus, the semihard momentum region $Q_s<k<Q_s/\sqrt{{\alpha }_s{N}_c}$ arises as a well-defined intermediate regime between the perturbatively hard momenta and the nonperturbative soft momenta $k<Q_s$ in the CGC description of a hadronic wave function.

We present a high statistics study of the isovector nucleon charges and form factors using seven ensembles of $2+1$-flavor Wilson-clover fermions. The axial vector and pseudoscalar form factors obtained on each of these ensembles satisfy the partially conserved axial current relation between them once the lowest energy $N\pi$ excited state is included in the spectral decomposition of the correlation functions used for extracting the ground state matrix elements. Similarly, we find evidence that the $N\pi \pi$ excited state contributes to the correlation functions with the insertion of the vector current, consistent with the vector meson dominance model. The resulting form factors are consistent with the Kelly parametrization of the experimental electric and magnetic data. Our final estimates for the isovector charges are $g_A^{u-d}=1.32(6)(5{)}_{\mathrm{sys}}$, $g_S^{u-d}=1.06(9)(6{)}_{\mathrm{sys}}$, and $g_T^{u-d}=0.97(3)(2{)}_{\mathrm{sys}}$, where the first error is the overall analysis uncertainty and the second is an additional combined systematic uncertainty. The form factors yield: (i) the axial charge radius squared, ${⟨r_A^2⟩}^{u-d}=0.428(53)(30{)}_{\mathrm{sys}}{\mathrm{fm}}^2$; (ii) the induced pseudoscalar charge, $g_P^{*}=7.9(7)(9{)}_{\mathrm{sys}}$; (iii) the pion-nucleon coupling, $g_{\pi \mathrm{NN}}=12.4(1.2)$; (iv) the electric charge radius squared, ${⟨r_E^2⟩}^{u-d}=0.85(12)(19{)}_{\mathrm{sys}}{\mathrm{fm}}^2$; (v) the magnetic charge radius squared, ${⟨r_M^2⟩}^{u-d}=0.71(19)(23{)}_{\mathrm{sys}}{\mathrm{fm}}^2$; and (vi) the magnetic moment, ${\mu }^{u-d}=4.15(22)(10{)}_{\mathrm{sys}}$. All our results are consistent with phenomenological/experimental values but with larger errors. Last, we present a Padé parametrization of the axial, electric, and magnetic form factors over the range $0.04<Q^2<1{\mathrm{GeV}}^2$ for phenomenological studies.

Unusual constituent quark axial current couplings to light vector mesons, $\rho$ and $\omega$, are derived in the vacuum and under weak magnetic field by considering a quark-antiquark interaction mediated by a nonperturbative gluon exchange. Similarly, light axial mesons are found to couple anomalously with the constituent quark vector current. These interactions are of the type of the Wess-Zumino-Witten terms, being strongly anisotropic and dependent on the vector (or axial) meson polarization. They also provide axial (vector) form factors for the vector (axial) mesons and are quite small, suppressed nearly by $1/{M^{*}}^2$ with respect to the vector mesons minimal coupling to the quark vector current. Some three-leg meson vertices are also presented: $\pi -\rho -A_1$ and $V_1{V}_{2}A$ (where $V_1$, $V_2$ are vector mesons and $A$ an axial meson). A vector and axial-vector mesons mixing is identified at nonzero magnetic field which however can contribute only in the presence of a third particle or in a medium. Numerical results are presented for different effective gluon propagators.

In the present work, we investigate the ${\eta }_{c}K$, $J/\psi K$, ${\eta }_c{K}^{*}$, and $J/\psi K^{*}$ hidden-charm decay modes for the $c\overline{c}s\overline{u}$ four-quark system in the molecular and compact tetraquark scenarios using the quark-exchange model. Our theoretical results indicate that if the newly observed states $Z_{cs}(3985)$ and $Z_{cs}(4000)$ are two different states, $Z_{cs}(4000)$ may be interpreted as the mixture $\frac{1}{\sqrt{2}}(D^0{D}_s^{*-}+D^{*0}{D}_s^{-})$, of which the $J/\psi K$ partial decay width is about $\mathrm{\Gamma }\sim 2.89\mathrm{MeV}$, while $Z_{cs}(3985)$ may be explained as the mixture $\frac{1}{\sqrt{2}}(-D^0{D}_s^{*-}+D^{*0}{D}_s^{-})$, of which the $J/\psi K$ partial decay width is small to zero. Moreover, if the state $Z_{cs}(4000)$ can be explained as the mixed state $\frac{1}{\sqrt{2}}(D^0{D}_s^{*-}+D^{*0}{D}_s^{-})$, indeed, the partial decay width ratio between $J/\psi K$ and ${\eta }_c{K}^{*}$ is close to unit, which indicates the decay channel ${\eta }_c{K}^{*}$ may be a ideal channel as well to decode the inner structure of $Z_{cs}(4000)$. In addition, the partial decay width for the tensor molecular state $|D^{*0}{D}_s^{*-}{⟩}_{2^{+}}$ decaying into $J/\psi K^{*}$ can reach up to a few MeV, which shows this tensor molecular state has a good potential to be observed in this decay channel.

We revisit the classic database of weighted-${\mathbb{P}}^4\mathrm{s}$ which admit Calabi-Yau 3-fold hypersurfaces equipped with a diverse set of tools from the machine-learning toolbox. Unsupervised techniques identify an unanticipated almost linear dependence of the topological data on the weights. This then allows us to identify a previously unnoticed clustering in the Calabi-Yau data. Supervised techniques are successful in predicting the topological parameters of the hypersurface from its weights with an accuracy of $R^2>95\%$. Supervised learning also allows us to identify weighted-${\mathbb{P}}^4\mathrm{s}$ which admit Calabi-Yau hypersurfaces to 100% accuracy by making use of partitioning supported by the clustering behavior.

We investigate the degradation of quantum entanglement in the Schwarzschild-de Sitter black hole spacetime, by studying the mutual information and the logarithmic negativity for maximally entangled, bipartite states for massless minimal scalar fields. This spacetime is endowed with a black hole as well as a cosmological event horizon, giving rise to particle creation at two different temperatures. We consider two independent descriptions of thermodynamics and particle creation in this background. The first involves thermal equilibrium of an observer with either of the horizons. We show that as of the asymptotically flat/anti–de Sitter black holes, in this case, the entanglement or correlation degrades with increasing Hawking temperatures. The second treats both the horizons combined in order to define a total entropy and an effective equilibrium temperature. We present a field theoretic derivation of this effective temperature and show that unlike the usual cases, the particle creation does not occur here in causally disconnected spacetime wedges but instead in a single region. Using the associated vacua, we show that in this scenario, the entanglement never degrades but increases with increasing black hole temperature and holds true no matter how hot the black hole becomes or how small the cosmological constant is. We argue that this phenomenon can have no analogue in the asymptotically flat/anti–de Sitter black hole spacetimes.

We extend our previous work in which we derived the most general form of an induced metric describing the geometry of an axially symmetric extremal isolated horizon (EIH) in asymptotically flat spacetime. Here we generalize it to EIHs in asymptotically (anti–)de Sitter spacetime. The resulting metric conveniently forms a six-parameter family which, in addition to a cosmological constant $\mathrm{\Lambda }$, depends on the area of the horizon, total electric and magnetic charges, and two deficit angles representing conical singularities at poles. Such a metric is consistent with results obtained in the context of near-horizon geometries. Moreover, we study extremal horizons of all black holes within the class of Plebański-Demiański exact (electro)vacuum spacetimes of the algebraic type D. In an important special case of nonaccelerating black holes, that is the famous Kerr-Newman-NUT-(A)dS metric, we were able to identify the corresponding extremal horizons, including their position and geometry, and find explicit relations between the physical parameters of the metric and the geometrical parameters of the EIHs.

A population of primordial black holes formed in the early Universe could contribute to at least a fraction of the black-hole merger events detectable by current and future gravitational-wave interferometers. With the ever-increasing number of detections, an important open problem is how to discriminate whether a given event is of primordial or astrophysical origin. We systematically present a comprehensive and interconnected list of discriminators that would allow us to rule out, or potentially claim, the primordial origin of a binary by measuring different parameters, including redshift, masses, spins, eccentricity, and tidal deformability. We estimate how accurately future detectors (such as the Einstein Telescope and LISA) could measure these quantities, and we quantify the constraining power of each discriminator for current interferometers. We apply this strategy to the GWTC-3 catalog of compact binary mergers. We show that current measurement uncertainties do not allow us to draw solid conclusions on the primordial origin of individual events, but this may become possible with next-generation ground-based detectors.

Axions are a theoretically promising dark matter (DM) candidate. In the presence of radiation from bright astrophysical sources at radio frequencies, nonrelativistic DM axions can undergo stimulated decay to two nearly back-to-back photons, meaning that bright sources of radio waves will have a counterimage (“gegenschein”) in nearly the exact opposite spatial direction. The counterimage will be spectrally distinct from backgrounds, taking the form of a narrow radio line centered at $\nu =m_a/4\pi$ with a width determined by Doppler broadening in the DM halo, $\mathrm{\Delta }\nu /\nu \sim {10}^{-3}$. In this work, we show that the axion decay-induced echoes of supernova remnants may be bright enough to be detectable. Their nondetection may be able to set the strongest limits to date on axion DM in the $\sim 1–10\mu \mathrm{eV}$ mass range where there are gaps in coverage from existing experiments.

We consider the possibility that the solar wind emits photons via bremsstrahlung when colliding with dark matter particles within the Solar System. To this effect, we calculate the bremsstrahlung spectrum that a proton would emit when colliding with a neutral spin-$1/2$ particle through the exchange of a scalar neutral particle. We assume a speed of $600\mathrm{km}/\sec$ for the solar wind and assume that the speed of the dark matter halo is due to the motion of the Sun through our Galaxy, which we take as $300\mathrm{km}/\sec$. We assume a dark matter density of $0.3\mathrm{GeV}/{\mathrm{cm}}^3$ and a solar wind composed primarily of protons with a total rate of ejection mass set at ${10}^9\mathrm{kg}/\sec$. We use a Monte Carlo technique to let this interaction take place within the Solar System and calculate the photon rate an observer would detect on Earth or at the edge of the Solar System as a function of photon energy. We find that the rates are in general very small but could be observable in some scenarios at wavelengths in the mm range at a telescope like ALMA; this could lead to interesting constraints on couplings and masses.

Space-time evolution of spin polarization within the framework of hydrodynamics with spin based on de Groot—van Leeuwen—van Weert forms of energy-momentum and spin tensors is studied. Due to the nonboost invariant flow in the system the spin polarization components couple to each other implying some effects on the spin polarization observables. We study transverse-momentum and rapidity dependence of mean spin polarization vector for $\mathrm{\Lambda }$ hyperons. Our results show qualitative agreement for rapidity dependence of the global spin polarization with the experiments and other models. The quadrupole structure of the longitudinal component at midrapidity is not found; however, as compared to the results for Bjorken expansion, some nontrivial signal at forward rapidities is observed.

We analyze the four-body $B\to \varphi (\to K\overline{K})K^{*}(\to K\pi )$ decays in the perturbative QCD approach, where the invariant mass of the $K\overline{K}$ ($K\pi$) system is limited in a window of $\pm 15\mathrm{MeV}$ ($\pm 150\mathrm{MeV}$) around the nominal $\varphi (K^{*}(892))$ mass. In addition to the dominant $P$-wave resonances, two important $S$-wave backgrounds in the selected invariant mass region are also accounted for. Angular momentum conservation allows six helicity amplitudes to contribute, including three $P$ waves, two single $S$ waves, and one double $S$ wave, in the decays under study. We calculated the branching ratio for each component and found sizable $S$-wave contributions, which coincide roughly with the experimental observation. The obtained branching ratios of $B^{0(+)}\to \varphi K^{*0(+)}$ are comparable with the previous theoretical predictions and support the experimental measurements, whereas the predicted $\mathcal{B}(B_s^0\to \varphi {\overline{K}}^{*0})$ is an order of magnitude smaller than the current world average in its central value. The longitudinal polarizations are predicted to be around 0.7, consistent with previous PQCD results but larger than the world average values. Aside from the direct $CP$ asymmetries, the true and fake triple product asymmetries, originating from the interference between the perpendicular polarization amplitude and other helicity amplitudes, are also calculated in this work. In the special case of the neutral modes, both the direct $CP$ asymmetries and true triple product asymmetries are expected to be zero due to the vanishing weak phase difference. The direct $CP$ asymmetries for the $B^{+}$ mode are predicted to be tiny, of order ${10}^{-2}$, since the tree contributions are suppressed strongly with respect to the penguin ones. The true triple product asymmetries have shown no significant deviations from zero. In contrast, large fake asymmetries are observed in these decays, indicating the presence of significant final-state interactions. We give the theoretical predictions of the $S$-wave induced triple product asymmetries for the first time, which is consistent with current LHCb data and would be checked with future measurements from Belle and BABAR experiments if the $S$-wave components can be properly taken into account in the angular analysis.

The analysis of azimuthal correlations in multiparticle production can be useful to uncover the existence of new physics beyond the Standard Model, e.g., Hidden Valley, in $e^{+}{e}^{-}$ annihilation at high energies. In this paper, based on previous theoretical studies and using the pythia8 event generator, it is found that both azimuthal and rapidity long-range correlations are enhanced due to the presence of a new stage of matter on top of the QCD partonic cascade. Ridge structures, similar to those observed in hadronic collisions at the LHC, show up providing a possible signature of new physics at future $e^{+}{e}^{-}$ colliders.

Dark matter direct detection experiments mostly operate at deep underground laboratories. It is necessary to consider shielding effect of the Earth, especially for dark matter particles interacting with a large cross section. We analyzed and simulated the Earth shielding effect for dark matter at the China Jinping Underground Laboratory (CJPL) with a simulation package, CJPL Earth Shielding Simulation code (CJPL_ESS), which is applicable to other underground locations. The further constraints on the $\chi \text{−}\mathrm{N}$ cross section exclusion regions are derived based on the studies with CDEX experiment data.