We consider relativistic fermionic systems in lattice regularization out of equilibrium. The chiral magnetic conductivity ${\sigma }_{\mathrm{CME}}$ is calculated in a spatially infinite system for the case when the chiral chemical potential depends on time, while the system initially was in thermal equilibrium at a small but nonzero temperature. We find that the frequency-dependent ${\sigma }_{\mathrm{CME}}(\omega )$ for any nonzero $\omega$ both in the limits $\omega \ll T$ and $\omega \gg T$ is equal to its conventional value 1 when the lattice model approaches the continuum limit. Notice that ${\sigma }_{\mathrm{CME}}=0$ for the case when the chiral chemical potential does not depend on time at all. We therefore confirm that the limit of vanishing $\omega$ is not regular for the spatially infinite systems of massless fermions.

It is shown that membrane and fivebrane of $\mathrm{D}=11$ supergravity theory can support nongauge, linearized spin-$3/2$ superhairs. Supercharges associated with these fields are calculated. We also generalize the solutions to some overlapping cases and discuss possible implications of their existence.

We present a new type of counterexample to the Nelson-Seiberg theorem. It is a generic $R$-symmetric Wess-Zumino model with nine chiral superfields, including one field of $R$-charge 2 and no $R$-charge 0 field. As in previous counterexamples, the model gives a set of degenerate supersymmetric vacua with a nonzero expectation value for a pair of oppositely $R$-charged fields. However, one of these fields appears quadratically in the superpotential, and many other fields with nonzero $R$ charges gain nonzero expectation values at the vacuum, and so this model escapes the sufficient condition for counterexamples established in previous literature. Thus there are still open problems in the relation of $R$ symmetries to supersymmetry breaking in generic models.

This work is motivated by the existence of mapping the extended theory of gravity with a standard energy-momentum tensor to general relativity with a modified energy-momentum tensor. We construct a modified anisotropic energy-momentum tensor from a standard isotropic energy-momentum tensor by adding a “geometrical correction” to precisely reproduce the Tolman-Oppenheimer-Volkoff equations predicted by the generalized Tolman-Oppenheimer-Volkoff (GTOV) model. This construction aims to calculate the moment of inertia ($I$) and tidal deformability ($\mathrm{\Lambda }$) of neutron stars (NSs) within the GTOV model. Therefore, we can comprehensively investigate the role of each free parameter of the GTOV model in NS properties. Furthermore, through this construction we can also utilize physically acceptable stability conditions for anisotropic stars to constrain the physical range of each parameter value and investigate the existence of a correlation among the parameters of the GTOV model. Except for $\alpha$, we find that the values of the GTOV free parameters can be limited to acceptable ranges. We also find that the parameters $\theta$, $\chi$, and $\beta$ are correlated, and the parameter $\mathrm{\Gamma }\to 0$. With these free parameter ranges in hand, we study the role of each parameter of the GTOV model in NS properties, including $I$ and $\mathrm{\Lambda }$. We also revisit the hyperon puzzle in NSs within the GTOV model. We find that the $\theta$ parameter plays a crucial role in controlling the NS maximum mass value. We also find that the threshold $k_2$ peak for NS is $k_2\approx 0.167$. Furthermore, if we use parameter sets with $\theta =-1$, the mass-radius predictions are compatible with recent NICER data on PSR $\mathrm{J}0030+0451$ and PSR $\mathrm{J}0740+6620$.

We consider a black hole mimicker given by an exact solution of the stationary and axially-symmetric field equations in vacuum known as the $\delta$-Kerr metric. We study its optical properties based on a ray-tracing code for photon motion and characterize the apparent shape of the shadow of the compact object and compare it with the Kerr black hole. For the purpose of obtaining qualitative estimates related to the observed shadow of the supermassive compact object in the galaxy M87 we focus on values of the object’s spin $a$ and inclination angle of observation ${\theta }_0$ close to the measured values. We then apply the model to the shadow of the $\delta$-Kerr metric to obtain constraints on the allowed values of the deformation parameter. We show that based uniquely on one set of observations of the shadow’s boundary it is not possible to exclude the $\delta$-Kerr solution as a viable source for the geometry in the exterior of the compact object.

Spin precession in merging black-hole binaries is a treasure trove for both astrophysics and fundamental physics. There are now well-established strategies to infer from gravitational-wave data whether at least one of the two black holes is precessing. In this paper we tackle the next-in-line target, namely the statistical assessment that the observed system has two precessing spins. We find that the recently developed generalization of the effective precession spin parameter ${\chi }_{\mathrm{p}}$ is a well-suited estimator to this task. With this estimator, the occurrence of two precessing spins is a necessary (though not sufficient) condition to obtain values $1<{\chi }_{\mathrm{p}}\le 2$. Confident measurements of gravitational-wave sources with ${\chi }_{\mathrm{p}}$ values in this range can be taken as a conservative assessment that the binary presents two precessing spins. We investigate this argument using a large set of $>100$ software injections assuming anticipated LIGO/Virgo sensitivities for the upcoming fourth observing run, O4. Our results are very encouraging, suggesting that, if such binaries exist in nature and merge at a sufficient rate, current interferometers are likely to deliver the first confident detection of merging black holes with two precessing spins. We investigate prior effects and waveform systematics and, though these need to be better investigated, did not find any confident false-positive case among all the configurations we tested. Our assessment should thus be taken as conservative.

The third observing run of the LIGO-Virgo Collaboration has resulted in many gravitational wave detections, including the binary neutron star merger GW190425. However, none of these events have been accompanied with an electromagnetic transient found during extensive follow-up searches. In this article, we perform new numerical-relativity simulations of binary neutron star and black hole-neutron star systems that have a chirp mass consistent with GW190425. Assuming that the GW190425’s sky location was covered with sufficient accuracy during the electromagnetic follow-up searches, we investigate whether the nondetection of the kilonova is compatible with the source parameters estimated through the gravitational-wave analysis and how one can use this information to place constraints on the properties of the system. Our simulations suggest that GW190425 is incompatible with an unequal mass binary neutron star merger with a mass ratio $q<0.8$ when considering stiff or moderately stiff equations of state if the binary was face on and covered by the observation. Our analysis shows that a detailed observational result for kilonovae will be useful to constrain the mass ratio of binary neutron stars in future events.

In the context of modified gravity, at the linear level, the growth of structure in the Universe will be affected by modifications to the Poisson equation and by the background expansion rate of the Universe. It has been shown that these two effects lead to a degeneracy which must be properly accounted for if one is to place reliable constraints on new forces on large scales or, equivalently, modifications to general relativity. In this paper we show that current constraints are such that assumptions about the background expansion have little impact on constraints on modifications to gravity. We do so by considering the background of a flat, $\mathrm{\Lambda }$ cold dark matter universe, a universe with a more general equation of state for the dark energy, and finally, a general, model-independent, expansion rate. We use Gaussian processes to model modifications to Poisson’s equation and, in the case of a general expansion rate, to model the redshift-dependent Hubble rate. We identify a degeneracy between modifications to Poisson’s equation and the background matter density, ${\mathrm{\Omega }}_M$, which can only be broken by assuming a model-dependent expansion rate. We show that, with current data, the constraints on modifications to the Poisson equation via measurements of the growth rate range between 10–20% depending on the strength of our assumptions on the Universe’s expansion rate.

Searching for variations of nature’s fundamental constants is a crucial step in our quest to go beyond our current standard model of fundamental physics. If they exist, such variations will be very likely driven by the existence of a new fundamental field. The Bekenstein model and its extensions introduce such a scalar field in a purely phenomenological way, inducing a variation of the fine-structure constant on cosmological scales. This theoretical framework is as simple and general as possible while still preserving all the symmetries of standard quantum electrodynamics. When allowing for couplings to the other sectors of the Universe, such as baryons, dark matter, and the cosmological constant, the Bekenstein model is expected to reproduce the low energy limits of several grand unification, quantum gravity, and higher dimensional theories. In this work, we constrain different versions of the Bekenstein model by confronting the full cosmological evolution of the field with an extensive set of astrophysical, cosmological, and local measurements. We show that couplings of the order of parts per million are excluded for all the cases considered, imposing strong restrictions on theoretical frameworks aiming to deal with variations of the fine-structure constant.

In this work, we investigate the effect of Population III (Pop. III) stars in ultracompact minihalos (UCMHs) on the cosmic ionization history using the Planck observation data. Although high-redshift astrophysics is not understood yet, UCMHs could host the Pop. III stars like the halos formed in the standard structure formation scenario. Such Pop. III stars would emit ionizing photons during their main sequence and facilitate cosmic reionization in high redshifts. To study their effects on the global ionization, we model the cosmic reionization evolution based on the “tanh”-type reionization model which is expressed by $z_{\mathrm{reio}}$ with additional two parameters characterizing the initial mass of UCMHs and the number density of UCMHs. We implement the Monte Carlo Markov Chain analysis with the latest Planck observation data for our reionization model. As the result, we found that if the UCMH initial mass is larger than ${10}^{8.4}{\mathrm{M}}_{\odot }$, the number density of UCMHs is strictly limited. Then we obtained the constraint on the amplitude of the primordial power spectrum through the constraint on the UCMH number density like ${\mathcal{A}}_{\zeta }\lesssim {10}^{-8}$ in the scales, $k\lesssim 50{\mathrm{Mpc}}^{-1}$, when we assume that the standard “tanh”-type reionization occurs by $z=3$, so that we set $z_{\mathrm{reio}}>3$.

We present high-fidelity cosmology results from a blinded joint analysis of galaxy-galaxy weak lensing ($\mathrm{\Delta }\mathrm{\Sigma }$) and projected galaxy clustering ($w_{\mathrm{p}}$) measured from the Hyper Suprime-Cam Year-1 (HSC-Y1) data and spectroscopic Sloan Digital Sky Survey (SDSS) galaxy catalogs in the redshift range $0.15<z<0.7$. We define luminosity-limited samples of SDSS galaxies to serve as the tracers of $w_{\mathrm{p}}$ in three spectroscopic redshift bins, and as the lens samples for $\mathrm{\Delta }\mathrm{\Sigma }$. For the $\mathrm{\Delta }\mathrm{\Sigma }$ measurements, we select a single sample of $4\times {10}^6$ source galaxies over $140{\mathrm{deg}}^2$ from HSC-Y1 with photometric redshifts (photo $z$) greater than 0.75, enabling a better handle of photo-$z$ errors by comparing the $\mathrm{\Delta }\mathrm{\Sigma }$ amplitudes for the three lens redshift bins. The deep, high-quality HSC-Y1 data enable significant detections of the $\mathrm{\Delta }\mathrm{\Sigma }$ signals, with integrated signal-to-noise ratio $S/N\sim 15$ in the range $3\le R/[h^{-1}\mathrm{Mpc}]\le 30$ for the three lens samples, despite the small area coverage. For cosmological parameter inference, we use an input galaxy-halo connection model built on the dark emulator package (which uses an ensemble set of high-resolution $N$-body simulations and enables fast, accurate computation of the clustering observables) with a halo occupation distribution that includes nuisance parameters to marginalize over modeling uncertainties. We model the $\mathrm{\Delta }\mathrm{\Sigma }$ and $w_{\mathrm{p}}$ measurements on scales from $R\simeq 3$ and $2h^{-1}\mathrm{Mpc}$, respectively, up to $30h^{-1}\mathrm{Mpc}$ (therefore excluding the baryon acoustic oscillations information) assuming a flat $\mathrm{\Lambda }\mathrm{CDM}$ cosmology, marginalizing over about 20 nuisance parameters and demonstrating the robustness of our results to them. With various tests using mock catalogs described in Miyatake et al. [preceding paper, Phys. Rev. D 106, 083519 (2022)], we show that any bias in the clustering amplitude $S_8\equiv {\sigma }_8({\mathrm{\Omega }}_{\mathrm{m}}/0.3{)}^{0.5}$ due to uncertainties in the galaxy-halo connection is less than $\sim 50\%$ of the statistical uncertainty of $S_8$, unless the assembly biaseffect is unexpectedly large. Our best-fit models have $S_8=0.795_{-0.042}^{+0.049}$ (mode and 68% credible interval) for the flat $\mathrm{\Lambda }\mathrm{CDM}$ model; we find tighter constraints on the quantity $S_8(\alpha =0.17)\equiv {\sigma }_8({\mathrm{\Omega }}_{\mathrm{m}}/0.3{)}^{0.17}=0.745_{-0.031}^{+0.039}$.

We present validation tests of emulator-based halo model method for cosmological parameter inference, assuming hypothetical measurements of the projected correlation function of galaxies, $w_{\mathrm{p}}(R)$, and the galaxy-galaxy weak lensing, $\mathrm{\Delta }\mathrm{\Sigma }(R)$, from the spectroscopic SDSS galaxies and the Hyper Suprime-Cam Year 1 (HSC-Y1) galaxies. To do this, we use dark emulator developed in Nishimichi et al. based on an ensemble of $N$-body simulations, which is an emulation package enabling a fast, accurate computation of halo clustering quantities (halo mass function, halo autocorrelation and halo-matter cross-correlation) for flat-geometry cold dark matter cosmologies. Adopting the halo occupation distribution, the emulator allows us to obtain model predictions of $\mathrm{\Delta }\mathrm{\Sigma }$ and $w_{\mathrm{p}}$ for the SDSS-like galaxies at a few CPU seconds for an input set of parameters. We present performance and validation of the method by carrying out Markov chain Monte Carlo analyses of the mock signals measured from a variety of mock catalogs that mimic the SDSS and HSC-Y1 galaxies. We show that the halo model method can recover the underlying true cosmological parameters to within the 68% credible interval, except for the mocks including the assembly bias effect (although we consider the unrealistically large amplitude of assembly bias effect). Even for the assembly bias mock, we demonstrate that the cosmological parameters can be recovered if the analysis is restricted to scales $R\gtrsim 10h^{-1}\mathrm{Mpc}$ (i.e., if the information on the average mass of halos hosting SDSS galaxies inherent in the 1-halo term of $\mathrm{\Delta }\mathrm{\Sigma }$ is not included). We also show that, by using a single population of source galaxies to infer the relative strengths of $\mathrm{\Delta }\mathrm{\Sigma }$ for multiple lens samples at different redshifts, the joint probes method allows for self-calibration of photometric redshift errors and multiplicative shear bias. Thus we conclude that the emulator-based halo model method can be safely applied to the HSC-Y1 dataset, achieving a precision of $\sigma (S_8)\simeq 0.04$ after marginalization over nuisance parameters such as the galaxy-halo connection parameters and the photo-$z$ error parameter, and our method is complementary to methods based on perturbation theory.

If the physics behind dark energy and/or dark matter violates the parity symmetry assumed in the standard cosmological paradigm, the linear polarization of the cosmic microwave background (CMB) photons can rotate due to their coupling to the dark sector. Recent $3\sigma$ hints of this “cosmic birefringence” in the $EB$ spectrum of the CMB polarization motivates us to pursue new directions to independently validate and characterize the signal. Here, we explore the prospects to probe cosmic birefringence from small-scale fluctuations in the CMB using polarized Sunyaev-Zel’dovich (pSZ) tomography. We find that pSZ can be used to infer the redshift dependence of cosmic birefringence and also help calibrate the instrumental polarization orientation. To illustrate the prospects, we show that pSZ tomography may probe an axion-like dark energy model with masses $m_{\varphi }\lesssim {10}^{-32}\mathrm{eV}$ with $\mathcal{O}(0.1)$ degrees of rotation between reionization and recombination.

This work investigates the formation of primordial black holes within a radiation fluid with an anisotropic pressure. We focus our attention on the initial conditions describing cosmological perturbations in the super horizon regime, using a covariant form of the equation of state in terms of pressure and energy density gradients. The effect of the anisotropy is to modify the initial shape of the cosmological perturbations with respect to the isotropic case. Using the dependence of the threshold ${\delta }_{\mathrm{c}}$ for primordial black holes with respect to the shape of cosmological perturbations, we estimate here how the threshold is varying with respect to the amplitude of the anisotropy. If this variation is large enough it could lead to a significant variation of the abundance of Primordial Black Holes.

Dark matter (DM) with a mass below a few keV must have a phase space distribution that differs substantially from the Standard Model particle thermal phase space: otherwise, it will free stream out of cosmic structures as they form. We observe that fermionic DM $\psi$ in this mass range will have a non-negligible momentum in the early Universe, even in the total absence of thermal kinetic energy. This is because the fermions were inevitably more dense at higher redshifts, and thus experienced Pauli degeneracy pressure. They fill up the lowest-momentum states, such that a typical fermion gains a momentum $\sim \mathcal{O}(p_F)$ that can exceed its mass $m_{\psi }$. We find a simple relation between $m_{\psi }$, the current fraction $f_{\psi }$ of the cold DM energy density in light fermions, and the redshift at which they were relativistic. Considering the impacts of the transition between nonrelativistic and relativistic behavior as revealed by constraints on $\mathrm{\Delta }{N}_{\mathrm{eff}}$ and the matter power spectrum, we derive qualitatively new bounds in the $f_{\psi }-m_{\psi }$ plane. We also improve existing bounds for $f_{\psi }=1$ to be $m_{\psi }\ge 2\mathrm{keV}$. We remark on implications for direct detection and suggest models of dark sectors that may give rise to cosmologically degenerate fermions.

There is growing interest in using current and future gravitational-wave interferometers to search for anisotropies in the gravitational-wave background. One guaranteed anisotropic signal is the kinematic dipole induced by our peculiar motion with respect to the cosmic rest frame, as measured in other full-sky observables such as the cosmic microwave background. Our prior knowledge of the amplitude and direction of this dipole is not explicitly accounted for in existing searches by LIGO/Virgo/KAGRA but could provide crucial information to help disentangle the sources which contribute to the gravitational-wave background. Here, we develop a targeted search pipeline which uses this prior knowledge to enable unbiased and minimum-variance inference of the dipole magnitude. Our search generalizes existing methods to allow for a time-dependent signal model, which captures the annual modulation of the dipole due to the Earth’s orbit. We validate our pipeline on mock data, demonstrating that neglecting this time dependence can bias the inferred dipole by as much as $\mathcal{O}(10\%)$. We then run our analysis on the full LIGO/Virgo $\mathrm{O}1+\mathrm{O}2+\mathrm{O}3$ dataset, obtaining upper limits on the dipole amplitude that are consistent with existing anisotropic search results.

Employing constraints derived from the microscopic theory of the strong interaction, we estimate the zero-temperature phase structure of dense isospin-asymmetric matter with two quark flavors. We find indications that strong-interaction matter along trajectories relevant for astrophysical applications undergoes a first-order phase transition from a color-superconducting phase to an ungapped quark-matter phase when the density is increased. Such a phase transition is found to be absent in isospin-symmetric matter. Moreover, by taking into account constraints from $\beta$ equilibrium, charge neutrality, and color neutrality, we provide an estimate for the speed of sound in neutron-star matter. Notably, we observe that the speed of sound in neutron-star matter exceeds the asymptotic value associated with the noninteracting quark gas and even increases toward lower densities across a wide range, in agreement with recent results for isospin-symmetric matter. Considering results from studies based on chiral effective field theory at low densities, our findings suggest the existence of a maximum in the speed of sound for $n/n_0\lesssim 10$, where $n_0$ is the nuclear saturation density.

We propose a novel class of composite models that feature both a technicolor and a composite Higgs vacuum limit, resulting in an asymmetric dark matter candidate. These techni-composite Higgs models are based on an extended left-right electroweak symmetry with a pseudo-Nambu Goldstone boson Higgs and stable dark matter candidates charged under a global $\mathrm{U}(1{)}_X$ symmetry, connected to the baryon asymmetry at high temperatures via the $\mathrm{SU}(2{)}_{\mathrm{R}}$ sphaleron. We consider, as explicit examples, four-dimensional gauge theories with fermions charged under a new confining gauge group $G_{\mathrm{HC}}$.

First results on the interaction between the $\varphi$-meson and the nucleon ($N$) are presented based on the ($2+1$)-flavor lattice QCD simulations with nearly physical quark masses. Using the HAL QCD method, the spacetime correlation of the $N\text{−}\varphi$ system in the spin $3/2$ channel is converted into the $N\text{−}\varphi$ scattering phase shift through the interaction potential. The $N\text{−}\varphi$ potential appears to be a combination of a short-range attractive core and a long-range attractive tail. The latter is found to be consistent with the two-pion exchange (TPE) obtained from the interaction between a color-dipole and the nucleon. The resultant scattering length and effective range for $m_{\pi }=146.4\mathrm{MeV}$ are $a_0^{(3/2)}=-1.43(23{)}_{\mathrm{stat}}({{}_{-06}^{+36})}_{\mathrm{syst}}\mathrm{fm}$ and $r_{\mathrm{eff}}^{(3/2)}=2.36(10{)}_{\mathrm{stat}}{({}_{-48}^{+02})}_{\mathrm{syst}}\mathrm{fm}$, respectively. The magnitude of the scattering length is shown to have nontrivial dependence of $m_{\pi }$ and is sensitive to the existence of the long-range tail from TPE.

We study the $\lambda {\varphi }^4$ model in $0+2$ dimensions at criticality, focusing on the scaling properties originating from the UV and IR physics. We demonstrate that the entanglement entropy, the correlation length $\xi$ and order parameters $\varphi$ and ${\varphi }^3$ exhibit distinctive double scaling properties that prove a powerful tool in the data analysis. The calculations are performed with boundary matrix product state methods on tensor network representations of the partition function to which the entanglement scaling hypothesis is applied, though the technique is equally applicable outside the realm of tensor networks. We find the value ${\alpha }_c=11.09698(31)$ for the critical point, improving on previous results.