We consider the analytic construction of three-point functions of conserved higher-spin supercurrents in three-dimensional $\mathcal{N}=1$ superconformal field theory which are Grassmann-odd in superspace. In particular, these include the three-point functions of the supercurrent and flavor currents, which contain the three-point functions of the energy-momentum tensor and conserved vector currents at the component level. We present an analytic proof for arbitrary superspins that these correlators do not possess a parity-violating contribution. We also prove that the parity-even contribution is unique, and exists (under an assumption that is well supported by the computational approach of arXiv:2302.00593) for arbitrary superspins. The construction of the parity-even sector is shown to reduce to solving a system of linear homogeneous equations with a tridiagonal matrix of corank one, which we solve explicitly for arbitrary superspins.

We consider a Reissner-Nordström black hole formed by the collapse of a charged null shell. The renormalized expectation values of the energy-momentum tensor operator for a massless scalar field propagating in the two-dimensional section of this spacetime are given. We then analyze the across-the-horizon correlations of the related energy density operator for free-falling observers to reveal the correlations between the Hawking particles and their interior partners.

In this work we first collect and generalize several existing nonperturbative models for the interaction between a single two-level qubit detector and a relativistic quantum scalar field in arbitrary curved spacetimes, where the time evolution is given by simple-generated unitaries, i.e., those generated by Schmidt rank-1 interaction Hamiltonians. We then extend the relativistic quantum channel associated to these nonperturbative models to include a very large class of Gaussian states of the quantum field, that includes an arbitrary combination of coherent and squeezing operations (i.e., Gaussian operations) on the field. We show that all physical results involving the nonvacuum Gaussian states can be rephrased in terms of interaction with the vacuum state but with Gaussian operators applied to the field operators via the adjoint channel, effectively giving a “Fourier transformed” interpretation of the Gaussian operations in terms of the causal propagators in spacetime. Furthermore, we show that in these nonperturbative models it is possible to perform exact computation of the Rényi entropy and hence, via the replica trick, the von Neumann entropy for the field state after the interaction with the detector, without making any assumptions about the purity of the joint initial states of the detector and the field. This gives us a three-parameter family of “generalized cat states” of the field whose entropies are finite and exactly computable.

The post-Newtonian formalism plays an integral role in the models used to extract information from gravitational wave data, but models that incorporate this formalism are inherently approximations. Disagreement between an approximate model and nature will produce mismodeling biases in the parameters inferred from data, introducing systematic error. We here carry out a proof-of-principle study of such systematic error by considering signals produced by quasicircular, inspiraling black hole binaries through an injection and recovery campaign. In particular, we study how unknown, but calibrated, higher-order post-Newtonian corrections to the gravitational wave phase impact systematic error in recovered parameters. As a first study, we produce injected data of nonspinning binaries as detected by a current, second-generation network of ground-based observatories and recover them with models of varying PN order in the phase. We find that the truncation of higher-order ($>3.5$) post-Newtonian corrections to the phase can produce significant systematic error even at signal-to-noise ratios of current detector networks. We propose a method to mitigate systematic error by marginalizing over our ignorance in the waveform through the inclusion of higher-order post-Newtonian coefficients as new model parameters. We show that this method can reduce systematic error greatly at the cost of increasing statistical error.

We present and discuss new families of primary hair charged black hole solutions in asymptotically anti–de Sitter space in three dimensions. The coupled Einstein-Maxwell-scalar gravity system, that carries the coupling $f(\varphi )$ between the scalar and Maxwell fields is solved, and exact hairy black hole solutions are obtained analytically. The hairy solutions are obtained for three different profiles of the coupling function: (i) $f(\varphi )=1$, corresponding to no direct coupling between the scalar and Maxwell fields; (ii) $f(\varphi )=e^{-\varphi }$; and (iii) $f(\varphi )=e^{-{\varphi }^2/2}$, corresponding to nonminimal coupling between them. For all these couplings the scalar field and curvature scalars are regular everywhere outside the horizon. We analyze the thermodynamics of the hairy black hole and find drastic changes in its thermodynamic structure due to the scalar field. For $f(\varphi )=1$, there exists a critical value of the hairy parameter above which the charged hairy black hole exhibits the Hawking/Page phase transition, whereas no such phase transition occurs below this critical value. Similarly, for $f(\varphi )=e^{-\varphi }$ and $f(\varphi )=e^{-{\varphi }^2/2}$, the hairy solution exhibits a small/large black hole phase transition for above critical values of the hairy parameter. Interestingly, for these couplings, the thermodynamic phase diagram of three-dimensional hairy charged black holes resembles that of a higher-dimensional Reissner-Nordström anti–de Sitter black hole, albeit with two second-order critical points.

We investigate the interplay between numerical relativity (NR) and point-particle black hole perturbation theory (ppBHPT) for quasi-circular nonspinning binary black holes in the intermediate mass ratio regime: $7\le q\le 128$ (where $q≔m_1/m_2$ is the mass ratio of the binary with $m_1$ and $m_2$ being the mass of the primary and secondary black hole respectively). Initially, we conduct a comprehensive comparison between the dominant $(\ell ,m)=(2,2)$ mode of the gravitational radiation obtained from state-of-the-art NR simulations and ppBHPT waveforms along with waveforms generated from recently developed NR-informed ppBHPT surrogate model, BHPTNRSur1dq1e4. This surrogate model employs a simple but nontrivial rescaling technique known as the $\alpha \text{−}\beta$ scaling to effectively match ppBHPT waveforms to NR in the comparable mass ratio regime. Subsequently, we analyze the amplitude and frequency differences between NR and ppBHPT waveforms to investigate the nonlinearities, beyond adiabatic evolution, that are present during the merger stage of the binary evolution and propose fitting functions to describe these differences in terms of both the mass ratio and the symmetric mass ratio. Finally, we assess the performance of the $\alpha \text{−}\beta$ scaling technique in the intermediate mass ratio regime.

We investigate the interplay between numerical relativity (NR) and point-particle black hole perturbation theory (ppBHPT) in the comparable mass ratio regime. In the ppBHPT framework, the secondary black hole is treated as a point particle, neglecting its finite size. Our study focuses on addressing the missing finite size effect in the ppBHPT framework and proposing a method for incorporating the size of the secondary into the perturbation theory framework. We demonstrate that by considering the secondary as a finite size object, the BHPT waveforms closely match NR waveforms. Additionally, we revisit the $\alpha \text{−}\beta$ scaling technique, which was previously introduced by Islam et al. [Phys. Rev. D 106, 104025 (2022)], as a means to effectively match ppBHPT waveforms to NR waveforms. We further analyze the scaling procedure and decompose it into different components, attributing them to various effects, including the corrections arising from the finite size of the secondary black hole.

Early dark energy (EDE) offers a solution to the so-called Hubble tension. Recently, it was shown that the constraints on EDE using Markov Chain Monte Carlo are affected by prior volume effects. The goal of this paper is to present constraints on the fraction of EDE, $f_{\mathrm{EDE}}$, and the Hubble parameter, $H_0$, which are not subject to prior volume effects. We conduct a frequentist profile likelihood analysis considering data from Planck cosmic microwave background, BOSS full-shape galaxy clustering, DES galaxy clustering and weak lensing, and the cosmic distance ladder from SH0ES. Contrary to previous findings, we find that $H_0$ for the EDE model is in statistical agreement with the SH0ES direct measurement at $<1.7\sigma$ for all datasets. For our baseline dataset ($Planck+\mathrm{BOSS}$), we obtain $f_{\mathrm{EDE}}=0.087\pm 0.037$ and $H_0=70.57\pm 1.36\mathrm{km}/\mathrm{s}/\mathrm{Mpc}$ at 68% confidence limit. We conclude that EDE is a viable solution to the Hubble tension.

We show that gravitational waves have the potential to unravel the microphysical properties of dark matter due to the dependence of the binary black hole merger rate on cosmic structure formation, which is itself highly dependent on the dark matter scenario. In particular, we demonstrate that suppression of small-scale structure—such as that caused by interacting, warm, or fuzzy dark matter—leads to a significant reduction in the rate of binary black hole mergers at redshifts $z\gtrsim 5$. This shows that future gravitational-wave observations will provide a new probe of physics beyond the $\mathrm{\Lambda }\mathrm{CDM}$ model.

The Universe’s matter inhomogeneity gravitationally affects the propagation of gravitational waves (GWs), causing the lensing effect. Particularly, the weak lensing of GWs has been studied within the range of the Born approximation to constrain the small-scale power spectrum. In this work, the validity of the Born approximation is investigated by accounting for the higher-order terms in the gravitational potential $\mathrm{\Phi }$. To do so, we formulate the post-Born approximation and derive the magnification $K$ and the phase modulation $S$ up to third order in $\mathrm{\Phi }$. We find that the average of $S$ and $K$ is nonzero and that the average of $S$ depends on the size of the point mass. Due to this size dependency, the signal is enhanced, and the number of GW events required for detecting the average of $S$ decreases. We find that this number can become comparable to or even smaller than the number required for detecting the variance of $S$ in certain scenarios. In addition, it is verified that, for lensing by dark low-mass halos, the post-Born corrections are a few orders of magnitude smaller than the Born approximation at $f\ge 0.01\mathrm{Hz}$. However, in the presence of the point mass, there is a condition under which the Born approximation fails. We derive the correction terms to the Born approximation and identify the condition under which the Born approximation no longer holds. For the magnification, the Born approximation is valid as long as the wavelength of GWs is larger than the Schwarzschild radius of lenses, while for the phase modulation, this condition is modified due to the physical size of the point mass.

Cosmic strings, if they exist, source nonlinear and non-Gaussian perturbations all the way back to the time of equal matter and radiation (and earlier). Here, we compute the mass function of halos seeded by a scaling distribution of cosmic string loops, and we compare the results with the predictions of the standard Gaussian $\mathrm{\Lambda }$ cold dark matter model. Assuming a simple linear relation between stellar mass and halo mass, we also compute the stellar mass function. The contribution of cosmic strings dominates at sufficiently high redshifts $z>z_c$ where $z_c$ depends on the mass of the halo and on the mass per unit length $\mu$ of the strings and is of the order $z_c\sim 12$ for $G\mu ={10}^{-8}$. We find that strings with this value of $G\mu$ can explain the preliminary James Webb Space Telescope (JWST) data on the high-redshift stellar mass density. Based on an extreme value statistic, we find that the mass of the heaviest expected string-seeded galaxy for the current JWST sky coverage is compatible with the heaviest detected galaxy. Given the uncertainties in the interpretation of the JWST data, we discuss predictions for higher redshift observations.

We present a machine learning approach, based on the genetic algorithms (GA), that can be used to reconstruct the inflationary potential directly from cosmological data. We create a pipeline consisting of the GA, a primordial code and a Boltzmann code used to calculate the theoretical predictions, and cosmic microwave background (CMB) data. As a proof of concept, we apply our methodology to the Planck CMB data and explore the functional space of single-field inflationary potentials in a nonparametric, yet analytical way. We show that the algorithm easily improves upon the vanilla model of quadratic inflation and proposes slow-roll potentials better suited to the data, while we confirm the robustness of the Starobinsky inflation model (and other small-field models). Moreover, using unbinned CMB data, we perform a first concrete application of the GA by searching for oscillatory features in the potential in an agnostic way, and find very significant improvements upon the best featureless potentials, $\mathrm{\Delta }{\chi }^2<-20$. These encouraging preliminary results motivate the search for resonant features in the primordial power spectrum with a multimodal distribution of frequencies. We stress that our pipeline is modular and can easily be extended to other CMB data sets and inflationary scenarios, like multifield inflation or theories with higher-order derivatives.

The large neutrino density in the deep interior of core-collapse supernovae and compact binary merger remnants makes neutrino flavor evolution nonlinear because of the coherent forward scattering of neutrinos among themselves. Under the assumption of spherical symmetry, we model neutrino decoupling from matter in an idealized setup and present the first nonlinear simulation of flavor evolution in the presence of charged current and neutral current collisions, as well as neutrino advection. Within our framework, we find that flavor transformation occurs before neutrinos fully decouple from matter, dynamically affecting the flavor distributions of all neutrino species and shifting the location of the neutrino decoupling surfaces. Our results call for further work as they may have implications on the explosion mechanism of supernovae, the nucleosynthesis of the heavy elements, as well as the observable neutrino signal, all of which is yet to be assessed.

We explore a novel method for measuring the time averaged temperature of the ${\nu }_x$ component in type-II core-collapse supernovae. By measuring neutral current incoherent neutrino-argon interactions in DUNE we can obtain spectral information for the combination of all active neutrino species. Combining this all-neutrino spectral information with detailed charged current measurements of the electron neutrino and electron antineutrino fluxes from DUNE and Hyper-Kamiokande, we can infer the time averaged temperature for the remaining neutrino species in the ${\nu }_x$ component to within a factor 2 for most cases and to 30% for a small range of time averaged ${\nu }_x$ temperatures. Because of the limited energy range of the emitted photons from incoherent neutral current interactions on argon, the ${\nu }_x$ temperature reconstruction demonstrates a degeneracy in the one and two sigma credible regions. Furthermore, while large uncertainties on the neutral current (NC) cross section penalize this measurement, we examined the efficacy of constraining NC cross section uncertainties on improving ${\nu }_x$ measurements. We found that if additional measurements of $\mathrm{B}(\mathrm{M}1\uparrow )$ $1^{+}$ excited state transitions in argon are able to reduce correlated cross section uncertainties from 15% to 7%, the size of the $1\sigma$ allowed regions for $T_{{\nu }_x}$ becomes sample size limited, and approaches the case where there are no uncertainties on the cross section.

We formulate an $S$-matrix theory in which localization effects of the particle interactions involved in a scattering process are consistently taken into account. In the limit of an infinite spread of all interactions, the $S$-matrix assumes its standard form. To better understand the significance of the emerging quantum phenomena in this formalism, we consider a solvable field-theoretic model with spatial Gaussian spreads at the interaction vertices. This solvable model, which was previously introduced in the literature, enables accurate descriptions of detection regions that are either close to or far from the source. In close analogy with light diffraction in classical optics, we call these two regions near-field and far-field zones, or the Fresnel and Fraunhofer regions. We revisit the question whether mixed mediators produce an oscillating pattern if their detection occurs in the Fresnel region. Besides corroborating certain earlier findings of the $S$-matrix amplitude in the forward Fresnel and Fraunhofer regimes, we observe several novel features with respect to its angular dependence which have not been accounted before in the literature. In particular, we obtain a “quantum obliquity factor” that suppresses particle propagation in the backward direction, thereby providing an explicit quantum field-theoretic description for its origin in diffractive optics. Present and future colliders, as well as both short and long baseline neutrino experiments, would greatly benefit from the many predictions that can be offered from such a holistic localized $S$-matrix theory.

We initiate a study of the gravitational-wave signatures of a phase transition that occurs as the Universe’s temperature increases during reheating. The gravitational-wave signatures of such a heating phase transition are different from those of a cooling phase transition, and their detection could allow us to probe reheating. In the lucky case that the gravitational-wave signatures from both the heating and cooling phase transitions were to be observed, information about reheating could in principle be obtained utilizing the correlations between the two transitions. Frictional effects, leading to a constant bubble wall speed in one case, will instead behave as an “antifriction” force in the other and accelerate the bubble wall. This antifriction will often take the bubble into a runaway regime, significantly enhancing the amplitude of the heating phase transition gravitational-wave signal. The efficiency, strength, and duration of the phase transitions will be similarly correlated in a reheating-dependent way.

We study fermion zero-modes in magnetized $T^6/{\mathbb{Z}}_N$ orbifold models. In particular, we focus on nonfactorizable orbifolds, i.e., $T^6/{\mathbb{Z}}_7$ and $T^6/{\mathbb{Z}}_{12}$ corresponding to $SU(7)$ and $E_6$ Lie lattices, respectively. The number of degenerated zero-modes corresponds to the generation number of low-energy effective theory in four-dimensional (4D) spacetime. We find that three-generation models preserving 4D $\mathcal{N}=1$ supersymmetry can be realized by magnetized $T^6/{\mathbb{Z}}_{12}$, but not by $T^6/{\mathbb{Z}}_7$. We use $Sp(6,\mathbb{Z})$ modular transformation for the analyses.

We analyze the leading and higher-order quantum electrodynamic corrections to the energy levels for a single electron bound in a Penning trap, including the Bethe logarithm correction due to virtual excitations of the reference quantum cyclotron state. The effective coupling parameter ${\alpha }_c$ in the Penning trap is identified as the square root of the ratio of the cyclotron frequency, converted to an energy via multiplication by the Planck constant, to the electron rest mass energy. We find a large, state-independent, logarithmic one-loop self-energy correction of order $\alpha {\alpha }_c^{4}m{c}^2\ln ({\alpha }_c^{-2})$, where $m$ is the electron rest mass and $c$ is the speed of light. Furthermore, we find a state-independent “trapped” Bethe logarithm. We also obtain a state-dependent higher-order logarithmic self-energy correction of order $\alpha {\alpha }_c^{6}m{c}^2\ln ({\alpha }_c^{-2})$. In the high-energy part of the bound-state self-energy, we need to consider terms with up to six magnetic interaction vertices inside the virtual photon loop.

A number of proposals have been put forward for detecting axion dark matter (DM) with grand unification scale decay constants that rely on the conversion of coherent DM axions to oscillating magnetic fields in the presence of static, laboratory magnetic fields. Crucially, such experiments—including ABRACADABRA—have to date worked in the limit that the axion Compton wavelength is larger than the size of the experiment, which allows one to take a magnetoquasistatic (MQS) approach to characterize the detector apparatus and model the axion signal. We use finite element methods to solve the coupled axion-electromagnetism equations of motion without assuming the MQS approximation. We show that the MQS approximation becomes a poor approximation at frequencies 2 orders of magnitude lower than the naive MQS limit frequency commonly defined by the inverse diameter of a lumped-element detector. Radiation losses diminish the quality factor of an otherwise high-$Q$ resonant readout circuit, though this may be mitigated through shielding and minimizing lossy materials. Additionally, self-resonances associated with the detector geometry change the reactive properties of the pickup system, leading to two generic features beyond MQS: There are frequencies that require an inductive rather than capacitive tuning to maintain resonance, and the detector itself becomes a multipole resonator at high frequencies. Accounting for these features, competitive sensitivity to the axion-photon coupling may be extended well beyond the naive MQS limit.