We explore nonrelativistic limits of $\mathcal{N}=1$ quiver gauge theories in 5d. The stringy counterpart of these Super Conformal Field Theories (SCFTs) is characterized by torsional string Newton-Cartan (TSNC) sigma models which are defined over non-Lorentzian manifolds. We further show that under transverse T duality, these TSNC sigma models are mapped into another new class of nonrelativistic sigma models which are defined over a T-dual TSNC background. Considering nonrelativistic limits of various field theory observables in a holographic setup, we further estimate corresponding entities in the TSNC limit of $\mathcal{N}=1$ quivers. We carry out a parallel analysis on holomorphic functions and the associated pole structures in the nonrelativistic limit of ($p$, $q$) five brane webs. In particular, we investigate the generic structure of various loop operators in a nonrelativistic setup and explore their properties under S duality. Finally, we comment on the large $c$ limit of Ramond-Ramond (RR) fields and discuss the associated S-duality transformation rules in the nonrelativistic limit of $\mathcal{N}=1$ quivers.

In vacuum, the gravitational recoil of the final black hole from the merger of two black holes depends exclusively on the mass ratio and spins of the coalescing black holes, and on the eccentricity of the binary. If matter is present, accretion by the merging black holes may modify significantly their masses and spins, altering both the dynamics of the binary and the gravitational recoil of the remnant black hole. This paper considers such a scenario. We investigate the effects on the kick of the final black hole from immersing the binary in a scalar field cloud. We consider two types of configurations: one with nonspinning and unequal-mass black holes, and a second with equal mass and spinning holes. For both types, we investigate how the gravitational recoil of the final black hole changes as we vary the energy density of the scalar field. We find that the accretion of the scalar field by the merging black holes could have a profound effect. For the nonspinning, unequal-mass binary black holes, the kicks are in general larger than in the vacuum case, with speeds of $\sim 1,200\mathrm{km}/\mathrm{s}$ for binaries with mass ratio $2:1$, 1 order of magnitude larger than in vacuum. For equal mass, binaries with black holes with spins aligned with the orbital angular momentum, kicks larger than in vacuum are also found. For systems with spins in the superkick configuration, the scalar field triggers a similar dependence of the kicks with the entrance angle at merger as in the vacuum case but in this case depending on the strength of the scalar field.

We investigate a nonsingular black hole spacetime representing a strong deformation of the Schwarzschild solution with mass $M$ by an additional hair $\ell$, which may be hierarchically larger than the Planck scale. The spacetime is an exact solution of Einstein’s equations sourced by an anisotropic fluid. The model presents a de Sitter core and $\mathcal{O}({\ell }^2/r^2)$ slow-decaying corrections to the Schwarzschild solution. These solutions are thermodynamically preferred when $0.2\lesssim \ell /GM\lesssim 0.3$ and are characterized by strong deviations in the orbits of test particles from the Schwarzschild case. In particular, we find corrections to the perihelion precession angle scaling linearly with $\ell$. We test our model using the available data for the orbits of the S2 star around ${\text{SgrA}}^{*}$. These data strongly constrain the value of the hair $\ell$, casting an upper bound on it of $\sim 0.47GM$ but do not rule out the possible existence of regular black holes with super-Planckian hair.

We have added support for realistic, microphysical, finite-temperature equations of state (EOS) and neutrino physics via a leakage scheme to illinoisgrmhd, an open-source GRMHD code for dynamical spacetimes in the einstein toolkit. These new features are provided by two new, nrpy+-based codes: nrpyeos, which performs highly efficient EOS table lookups and interpolations, and nrpyleakage, which implements a new, adaptive mesh refinement (AMR)-capable neutrino leakage scheme in the einstein toolkit. We have performed a series of strenuous validation tests that demonstrate the robustness of these new codes, particularly on the Cartesian AMR grids provided by carpet. Furthermore, we show results from fully dynamical GRMHD simulations of single unmagnetized neutron stars, and magnetized binary neutron star mergers. This new version of illinoisgrmhd, as well as nrpyeos and nrpyleakage, is pedagogically documented in jupyter notebooks and fully open source. The codes will be proposed for inclusion in an upcoming version of the einstein toolkit.

Finding signatures of dark matter in transport characteristics of solids would be an important step on the road to detect this illusive component of the mass of our Universe. This is especially important and timely as the experiments designed to directly detect dark matter particles continue to provide negative results. As a first step in this direction we consider topologically nontrivial Weyl or Dirac semimetals and derive the modified kinetic equation taking into account two coupled $U(1)$-gauge fields, one being the standard Maxwell electromagnetic field and other corresponding to the dark sector. The resulting Boltzmann kinetic equation is modified by the Berry curvature which couples to both visible and dark sector gauge fields. It was revealed that the dark sector induces modifications of transport coefficients due to the appearance of coupling constant between gauge fields and dark sector magnetic field.

We study the generation of local non-Gaussianity in models of canonical single field inflation when their backgrounds are either attractor or nonattractor. We show that the invariance of inflation under space-time diffeomorphisms can be exploited to make powerful statements about the squeezed limit of the primordial bispectrum of curvature perturbations, valid to all orders in slow roll parameters. In particular, by neglecting departures from the adiabatic evolution of long-wavelength modes (for instance, produced in sharp transitions between slow-roll and ultraslow-roll phases), we derive a general expression for the bispectrum’s squeezed limit in comoving coordinates. This result consists in the standard Maldacena’s consistency relation (proportional to the spectral index of the power spectrum) plus additional terms containing time derivatives of the power spectrum. In addition, we show that it is always possible to write the perturbed metric in conformal Fermi coordinates, independently of whether the inflationary background is attractor or nonattractor, allowing the computation of the physical primordial bispectrum’s squeezed limit as observed by local inertial observers. We find that in the absence of sudden transitions between attractor and nonattractor regimes, observable local non-Gaussianity is generically suppressed. Our results imply that large local non-Gaussianity is not a generic consequence of nonattractor backgrounds.

We provide a novel approach to calculate the gravitational form factor of pion under the ladder approximation of the Bethe-Salpeter equation, with contact interactions. Central to this approach is a symmetry-preserving treatment of the dressed $\pi \pi$ amplitude, which shows explicitly the contributions from intrinsic quarks and bound states, the latter being necessary to produce the $D$-term of pion in the soft-pion limit. The approach we provide in this work can be applied to many processes of physical significance.

We present a study of rare decay modes $B^{+}\to D_s^{+}{h}^0$, $B^{+}\to D_s^{*+}{h}^0$, and $B^{+}\to D^{+}{h}^0$, where $h^0$ denotes the neutral meson $\eta$ or $K^0$, using a data sample of $(772\pm 10)\times {10}^{6}B\overline{B}$ events produced at the $\mathrm{\Upsilon }(4S)$ resonance. The data were collected by the Belle detector operating at the asymmetric-energy KEKB collider. We find no evidence for these decays, so we set upper limits at the 90% confidence level on the branching fractions of $B^{+}\to D_s^{+}{h}^0$, $D_s^{*+}{h}^0$, and $D^{+}{h}^0$ decay modes. Along with these rare decay modes, we report improved measurements of the color-suppressed decay branching fractions $\mathcal{B}({\overline{B}}^0\to D^0\eta )=(26.6\pm 1.2\pm 2.1)\times {10}^{-5}$ and $\mathcal{B}({\overline{B}}^0\to D^0{\overline{K}}^0)=(5.6\pm 0.5\pm 0.2)\times {10}^{-5}$. The first and second quoted uncertainties are statistical and systematic, respectively.

By extending the recent analysis [G. Gold, S. Khandelwal, W. Kitchin, and G. Tartaglino-Mazzucchelli, J. High Energy Phys. 09 (2022) 016] for $\mathcal{N}=2$ conformal supergravity in four dimensions, we define new hyperdilaton Weyl multiplets for five-dimensional $\mathcal{N}=1$ and six-dimensional $\mathcal{N}=(1,0)$ conformal supergravities. These are constructed by coupling the five- and six-dimensional standard Weyl multiplets to on-shell hypermultiplets and reinterpreting the systems as new multiplets of conformal supergravity. In the five-dimensional case, we also construct a new hyperdilaton Poincaré supergravity by coupling to an off-shell vector multiplet compensator. As in four dimensions, a $BF$ coupling induces a nontrivial scalar potential for the five-dimensional dilaton that admits ${\mathrm{AdS}}_5$ vacua.

The invariance of physical observables like particle’s mass under a local field redefinition is a well-known and important property of quantum field theory. In this paper, on the other hand, we investigate nonlocal field redefinitions eliminating a physical observable from a theory. Indeed, by giving explicit examples, we present invertible nonlocal field redefinitions reducing a massive theory to the massless one, and vice versa. The studied examples are: classical harmonic oscillator, the scalar field theory, and the Dirac field theory.

Motivated by recent results reporting the instability of horizonless objects with stable light rings, we revisit the linearized stability of such structures. In particular, we consider an exterior Kerr spacetime truncated at a surface where Dirichlet conditions on a massless scalar are imposed. This spacetime has ergoregions and light rings when the surface is placed sufficiently deep in the gravitational potential. We establish that the spacetime is linearly, mode unstable when it is sufficiently compact, and in a mechanism associated with the ergoregion. In particular, such instability has associated zero modes. At large multipole number the critical surface location for zero modes to exist is precisely the location of the ergosurface along the equator. We show that such modes do not exist when the surface is outside the ergoregion, and that any putative linear instability mechanism acts on timescales $\tau \gtrsim {10}^{5}M$, where $M$ is the black hole mass. Our results indicate therefore that at least certain classes of objects are linearly stable in the absence of ergoregions, even if rotation and light rings are present.

We discuss slowly rotating, general relativistic, superfluid neutron stars in the Hartle-Thorne formulation. The composition of the stars is described by a simple two-fluid model which accounts for superfluid neutrons and all other constituents. We apply a perturbed matching framework to derive a new formalism for slowly rotating superfluid neutron stars, valid up to second order perturbation theory, building on the original formulation reported by Andersson and Comer in 2001. The present study constitutes an extension of previous work in the single-fluid case where it was shown that the Hartle-Thorne formalism needs to be amended since it does not provide the correct results when the energy density does not vanish at the surface of the star. We discuss in detail the corrections that need to be applied to the original two-fluid formalism in order to account for nonvanishing energy densities at the boundary. In the process, we also find a correction needed in the computation of the deformation of the stellar surface in the original two-fluid model in all cases (irrespective of the value of the energy density at the surface). The discrepancies found between the two formalisms are illustrated by building numerical stellar models, focusing on the comparison in the calculation of the stellar mass, the deformation of the star, and in the Kepler limit of rotation. In particular, using a toy-model equation of state for which the energy density does not vanish at the boundary of the star we demonstrate that the corrections to the formalism we find impact the structure of slowly rotating superfluid neutron stars in a significant way.

Using the spinning, supersymmetric worldline quantum field theory formalism we compute the momentum impulse and spin kick from a scattering of two spinning black holes or neutron stars up to quadratic order in spin at third post-Minkowskian (PM) order, including radiation-reaction effects and with arbitrarily misaligned spin directions. Parts of these observables, both conservative and radiative, are also inferred from lower-PM scattering data by extending Bini and Damour’s linear response formula to include misaligned spins. By solving Hamilton’s equations of motion we also use a conservative scattering angle to infer a complete 3PM two-body Hamiltonian including finite-size corrections and misaligned spin-spin interactions. Finally, we describe mappings to the bound two-body dynamics for aligned spin vectors: including a numerical plot of the binding energy for circular orbits compared with numerical relativity, analytic confirmation of the NNLO PN binding energy, and the energy loss over successive orbits.

The ensemble of unresolved compact binary coalescences is a promising source of the stochastic gravitational-wave (GW) background. For stellar-mass black hole binaries, the astrophysical stochastic GW background is expected to exhibit non-Gaussianity due to their intermittent features. We investigate the application of deep learning to detect such a non-Gaussian stochastic GW background and demonstrate it with the toy model employed by Drasco and Flanagan in 2003, in which each burst is described by a single peak concentrated at a time bin. For the detection problem, we compare three neural networks with different structures: a shallower convolutional neural network (CNN), a deeper CNN, and a residual network. We show that the residual network can achieve comparable sensitivity as the conventional non-Gaussian statistic for signals with the astrophysical duty cycle of ${\log }_{10}\xi \in [-3,-1]$. Furthermore, we apply deep learning for parameter estimation with two approaches in which the neural network (1) directly provides the duty cycle and the signal-to-noise ratio and (2) classifies the data into four classes depending on the duty cycle value. This is the first step of a deep learning application for detecting a non-Gaussian stochastic GW background and extracting information on the astrophysical duty cycle.

Accelerating black holes, connected to cosmic strings, could evolve to supermassive black holes. However, if they are going to take part in structure formation and reside at the center of galaxies, their acceleration should be small. This slow acceleration does not change the shadow or image position in a gravitational lensing effect significantly. However, we show that the time delay associated with these images does change significantly. This is in contrast to when the theory governing the strong gravitational field around the black hole is different from general relativity, where not only the differential time delays but the angular position of images would be different. We conclude that, if the observed angular position of images is compatible with the prediction of general relativity, a possible deviation in the differential time delays between the observed values and those predicted by general relativity could be due to the acceleration of the black hole.

We study the formation of primordial black holes and the generation of gravitational waves in a class of cosmological models that are direct supersymmetric analogs of the observationally favored nonminimally coupled Higgs inflation model. It is known that this type of model naturally includes multiple scalar fields which may be regarded as the inflaton. For the sake of simplicity we focus on the case where the inflaton field space is two dimensional. We analyze the multifield dynamics and find the region of parameters that gives copious production of primordial black holes that may comprise a significant part of the present dark matter abundance. We also compute the spectrum of the gravitational waves and discuss their detectability by means of future ground-based and space-borne gravitational wave observatories.

Various aspects of axion electrodynamics in the presence of a homogeneous and isotropic dielectric medium are discussed. First, we consider the “antenna-like” property of a planar dielectric surface in axion electrodynamics, elaborating on the treatment given earlier on this topic by Millar et al. [J. Cosmol. Astropart. Phys. 01 (2017) 061.]. We calculate the electromagnetic energy transmission coefficient for a dielectric plate, and compare with the conventional expression in ordinary electrodynamics. Second, we consider the situation where the medium exterior to the plate, assumed elastic, is “bent back” and glued together, so that we obtain a circular dielectric string in which the waves can propagate clockwise or counterclockwise. As will be shown, a stationary wave pattern is permitted by the formalism, and we show how the amplitudes for the two counterpropagating waves can be found. Third, as a special case, by omitting axions for a moment, we analyze the Casimir effect for the string, showing its similarity as well as its difference from the Casimir effect of a scalar field for a piecewise uniform string [I. Brevik and H. B. Nielsen, Phys. Rev. D 41, 1185 (1990).]. Finally, including axions again we analyze the enhancement of the surface-generated electromagnetic radiation near the center of a cylindrical haloscope, where the interior region is a vacuum and the exterior region a high refractive index medium. This enhancement is caused by the curvature of the boundary, and is mathematically a consequence of the behavior of the Hankel function of the second kind for small arguments. A simple estimate shows that enhancement may be quite significant, and can therefore be of experimental interest. The presence of an absorber in the center and the possibility of adopting it to search for axions with mass in the THz region, and possibly the GHz region too, is also discussed. This proposal is suggested as an alternative to the reflector arrangement in a similar arrangement recently discussed by Liu et al. [, Phys. Rev. Lett. 128, 131801 (2022).].

We develop an optimal Bayesian solution for jointly inferring secondary signals in the cosmic microwave background (CMB) originating from gravitational lensing and from patchy screening during the epoch of reionization. This method is able to extract full information content from the data, improving upon previously considered quadratic estimators for lensing and screening. We forecast constraints using the marginal unbiased score expansion method, and show that they are largely dominated by CMB polarization, and depend on the exact details of reionization. For models consistent with current data which produce the largest screening signals, a detection ($3\sigma$) of the cross-correlation between lensing and screening is possible with SPT-3G and a detection of the autocorrelation is possible with CMB-S4. Models with the lowest screening signals evade the sensitivity of SPT-3G but are still possible to detect with CMB-S4 via their lensing cross-correlation.

A model of the time-delayed electromagnetic cascade “echo” is applied to the bright gamma-ray burst GRB190114C—the first gamma-ray burst to be contemporaneously detected in high and very high-energy gamma-ray bands. It is shown that the internal spread of the cascade in the absence of the intervening magnetic fields dilutes the “echo” emission over ${10}^3–{10}^5$ seconds depending on the energy. Accounting for the measured source flux in the 0.3–1 TeV gamma-ray band, the prediction of the “echo” model is shown to match the detected lower-energy gamma-ray emission ${10}^4$ seconds after the burst. However, the “echo” emission remains indistinguishable from the intrinsic GRB190114C flux within the measurement uncertainties. Implications of this in the context of the intergalactic magnetic field measurement are discussed.