We examine the nonperturbative gauge dependence of arbitrary configuration space fermion correlators in quantum electrodynamics (QED). First, we study the dressed electron propagator (allowing for emission or absorption of any number of photons along a fermion line) using the first quantized approach to quantum field theory and analyze its gauge transformation properties induced by virtual photon exchange. This is then extended to the $N$-point functions where we derive an exact, generalized version of the fully nonperturbative Landau-Khalatnikov-Fradkin (LKF) transformation for these correlators. We discuss some general aspects of application in perturbation theory and investigate the structure of the LKF factor about $D=2$ dimensions.

For electromagnetic field theories, canonical energy-momentum conservation laws can be derived from the underpinning spacetime translation symmetry according to the Noether procedure. However, the canonical energy-momentum tensors (EMTs) are neither symmetric nor gauge-symmetric (gauge invariant). The Belinfante-Rosenfeld (BR) method is a well-known procedure to symmetrize the EMTs, which also renders them gauge symmetric for first-order field theories. High-order electromagnetic field theories appear in the study of gyrokinetic systems for magnetized plasmas and the Podolsky system for the radiation reaction of classical charged particles. For these high-order field theories, gauge-symmetric EMTs are not necessarily symmetric and vice versa. In the present study, we develop a new gauge-symmetrization method for EMTs in high-order electromagnetic field theories. The Noether procedure is carried out using the Faraday tensor $F_{\mu \nu }$, instead of the 4-potential $A_{\mu }$, to derive a canonical EMT $T_{\mathrm{N}}^{\mu \nu }$. We show that the gauge-dependent part of $T_{\mathrm{N}}^{\mu \nu }$ can be removed using the displacement-potential tensor ${\mathcal{F}}^{\sigma \mu \nu }\equiv {\mathcal{D}}^{\sigma \mu }{A}^{\nu }/4\pi$, where ${\mathcal{D}}^{\sigma \mu }$ is the antisymmetric electric displacement tensor. This method gauge-symmetrizes the EMT without necessarily making it symmetric, which is adequate for applications not involving general relativity. For first-order electromagnetic field theories, such as the standard Maxwell system, ${\mathcal{F}}^{\sigma \mu \nu }$ reduces to the familiar BR superpotential ${\mathcal{S}}^{\sigma \mu \nu }$, and the method developed can be used as a simpler procedure to calculate ${\mathcal{S}}^{\sigma \mu \nu }$ without employing the angular momentum tensor in 4D spacetime. When the electromagnetic system is coupled to classical charged particles, the gauge-symmetrization method for EMTs is shown to be effective as well.

The vector-tensor Horndeski theory is supplemented by a real, massless scalar field nonminimally coupled to the Horndeski interaction term. The generic dyonic Reissner-Nordstrom solutions characterized by electric and magnetic charges, acquire an instability and bifurcate into electromagnetically charged solutions presenting a horizon and a cloud of scalar hairs at specific values of the nonminimal coupling constant. These hairy black holes are studied in terms of the physical parameters of the model and the critical phenomena limiting their domain of existence are discussed.

While most binary inspirals are expected to have circularized before they enter the LIGO/Virgo frequency band, a small fraction of those binaries could have non-negligible orbital eccentricity depending on their formation channel. Hence, it is important to accurately model eccentricity effects in waveform models used to detect those binaries, infer their properties, and shed light on their astrophysical environment. We develop a multipolar effective-one-body (EOB) eccentric waveform model for compact binaries whose components have spins aligned or antialigned with the orbital angular momentum. The waveform model contains eccentricity effects in the radiation-reaction force and gravitational modes through second post-Newtonian (PN) order, including tail effects, and spin-orbit and spin-spin couplings. We recast the PN-expanded, eccentric radiation-reaction force and modes in factorized form so that the newly derived terms can be directly included in the state-of-the-art, quasi-circular–orbit EOB model currently used in LIGO/Virgo analyses (i.e., the SEOBNRv4HM model).

We present the nonrelativistic limit of the stellar structure equations of Ricci-based gravities, a family of metric-affine theories whose Lagrangian is built via contractions of the metric with the Ricci tensor of an a priori independent connection. We find that this limit is characterized by four parameters that arise in the expansion of several geometric quantities in powers of the stress-energy tensor of the matter fields. We discuss the relevance of this result for the phenomenology of nonrelativistic stars, such as main-sequence stars as well as several substellar objects.

We consider accelerated black hole horizons with and without defects. These horizons appear in the $C$-metric solution to Einstein equations and in its generalization to the case where external fields are present. These solutions realize a variety of physical processes, from the decay of a cosmic string by a black hole pair nucleation to the creation of a black hole pair by an external electromagnetic field. Here, we show that such geometries exhibit an infinite set of symmetries in their near horizon region, generalizing in this way previous results for smooth isolated horizons. By considering the limit close to both the black hole and the acceleration horizons, we show that a sensible set of asymptotic boundary conditions gets preserved by supertranslation and superrotation transformations. By acting on the geometry with such transformations, we derive the superrotated, supertranslated version of the $C$-metric and compute the associated conserved charges. We also consider other physical scenarios, including accelerated black holes in anti–de Sitter and binary black hole systems.

In a previous work [L. Asprea, G. Gasbarri, and A. Bassi, Gravitational decoherence: A general nonrelativistic model, Phys. Rev. D 103, 104041 (2021).] we derived a quantum master equation for the dynamics of a scalar bosonic particle interacting with a weak, stochastic and classical gravitational field. As standard matter is made of fermions, such an equation should be suitably extended to describe more relevant experimental situations. Here we derive a nonrelativistic model for the gravitational decoherence of spin 1/2 particles. We enrich the treatment by also considering a coupling with an external classical electromagnetic field. We comment on the differences with the scalar bosonic model and we describe the regimes in which they become negligible.

We study the gravitational radiation emitted during the scattering of two spinless bodies in the post-Minkowskian effective field theory approach. We derive the conserved stress-energy tensor linearly coupled to gravity and the classical probability amplitude of graviton emission at leading and next-to-leading order in the Newton’s constant $G$. The amplitude can be expressed in compact form as one-dimensional integrals over a Feynman parameter involving Bessel functions. We use it to recover the leading-order radiated angular momentum expression. Upon expanding it in the relative velocity between the two bodies $v$, we compute the total four-momentum radiated into gravitational waves at leading-order in $G$ and up to an order ${v,}^8$ finding agreement with what was recently computed using scattering amplitude methods. Our results also allow us to investigate the zero frequency limit of the emitted energy spectrum.

We prove a no Cauchy horizon theorem for general nonlinear electrodynamics black holes with charged scalar hairs. By constructing a radially conserved charged, we show that there is no inner Cauchy horizon for both spherical and planar symmetric cases, independent of the form of scalar potential and nonlinear electrodynamics. After imposing the null energy condition, we are also able to rule out the existence of the Cauchy horizon for the hyperbolic black holes. We take the Born-Infeld black hole as a concrete example to study the interior dynamics beyond the event horizon. When the contribution from the scalar potential can be neglected, the asymptotic near-singularity takes a universal Kasner form. We also confirm that the intricate interior dynamics is closely associated with the instability of the inner Cauchy horizon triggered by scalar hairs.

We check the dynamical and observational features of four typologies of logotropic dark energy models, leading to a thermodynamic cosmic speed up fueled by a single fluid that unifies dark energy and dark matter. We first present two principal Anton-Schmidt fluids where the Grüneisen parameter ${\gamma }_{\mathrm{G}}$ is free to vary and then fixed to the special value ${\gamma }_{\mathrm{G}}=\frac{5}{6}$. We also investigate the pure logotropic model, corresponding to ${\gamma }_{\mathrm{G}}=-\frac{1}{6}$. Finally, we propose a new logotropic paradigm that works as a generalized logotropic fluid, in which we split the role of dark matter and baryons. We demonstrate that the logotropic paradigms may present drawbacks in perturbations, showing a negative adiabatic sound speed which make perturbations unstable. We thus underline which model is favored over the rest. The Anton-Schmidt model with ${\gamma }_{\mathrm{G}}=\frac{5}{6}$ is ruled out while the generalized logotropic fluid seems to be the most suitable one, albeit weakly disfavored than the $\mathrm{\Lambda }\mathrm{CDM}$ model. To fix numerical constraints, we combine low- and higher-redshift domains through experimental fits based on Monte Carlo Markov Chain procedures, taking into account the most recent Pantheon supernovae Ia catalog, Hubble measurements, and ${\sigma }_8$ data points based on the linear growth function for the large scale structures. We also consider two model selection criteria to infer the statistical significance of the four models under examination. We conclude there is a statistical advantage to handle the Anton-Schmidt fluid with the Grüneisen parameter free to vary and/or fixed to ${\gamma }_{\mathrm{G}}=-\frac{1}{6}$. The generalized logotropic fluid indicates suitable results, more statistically favored than the other models until the sound speed is positive, becoming unstable in perturbations elsewhere. We emphasize that the $\mathrm{\Lambda }\mathrm{CDM}$ paradigm works statistically better than any kind of logotropic and generalized logotropic models, while the Chevallier-Polarski-Linder parametrization is statistically comparable with logotropic scenarios. Finally, we propose that generalizing the Grüneisen parameter by including the effects of temperature would guarantee the sound speed to be positive definite at all redshifts.

We consider dark matter which has nonzero electromagnetic form factors like electric/magnetic dipole moments and anapole moment for fermionic dark matter and Rayleigh form factor for scalar dark matter. We consider dark matter mass $m_{\chi }>\mathcal{O}(\mathrm{MeV})$ and put constraints on their mass and electromagnetic couplings from cosmic microwave background (CMB) and large scale structure (LSS) observations. Fermionic dark matter with nonzero electromagnetic form factors can annihilate to $e^{+}{e}^{-}$ and scalar dark matter can annihilate to $2\gamma$ at the time of recombination and distort the CMB. We analyze dark matter with multipole moments with Planck and baryon acoustic oscillations (BAO) observations. We find upper bounds on anapole moment $g_A<7.163\times {10}^3{\mathrm{GeV}}^{-2}$, electric dipole moment $\mathcal{D}<7.978\times {10}^{-9}e\mathrm{cm}$, magnetic dipole moment $\mu <2.959\times {10}^{-7}{\mu }_B$, and the bound on Rayleigh form factor of dark matter is $g_4/{\mathrm{\Lambda }}_4^2<1.085\times {10}^{-2}{\mathrm{GeV}}^{-2}$ with 95% C.L.

Accurate cosmological parameter estimates using polarization data of the cosmic microwave background (CMB) put stringent requirements on map calibration, as highlighted in the recent results from the Planck satellite. In this paper, we point out that a model-dependent determination of polarization calibration can be achieved by the joint fit of the temperature-E-mode cross-power spectrum (TE) and E-mode auto-power spectrum (EE). This provides a valuable cross-check to band-averaged polarization efficiency measurements determined using other approaches. We demonstrate that, in $\mathrm{\Lambda }\mathrm{CDM}$, the combination of the TE and EE constrain polarization calibration with sub-percent uncertainty with Planck data and 2% uncertainty with sptpol data. We arrive at similar conclusions when extending $\mathrm{\Lambda }\mathrm{CDM}$ to include the amplitude of lensing $A_{\mathrm{L}}$, the number of relativistic species $N_{\mathrm{eff}}$, or the sum of the neutrino masses $\sum m_{\nu }$. The uncertainties on cosmological parameters are minimally impacted when marginalizing over polarization calibration, except, as can be expected, for the uncertainty on the amplitude of the primordial scalar power spectrum $\ln ({10}^{10}{A}_{\mathrm{s}})$, which increases by 20–50%. However, this information can be fully recovered by adding temperature auto-power spectrum (TT) information. For current and future ground-based experiments, SPT-3G and CMB-S4, we forecast the cosmological parameter uncertainties to be minimally degraded when marginalizing over polarization calibration parameters. In addition, CMB-S4 could constrain its polarization calibration at the level of $\sim 0.2\%$ by combining TE and EE, and reach $\sim 0.06\%$ by also including TT. We therefore conclude that relying on calibrating against Planck polarization maps, whose statistical uncertainty is limited to $\sim 0.5\%$, would be insufficient for upcoming experiments.

We constrain the lifetime of thermally produced heavy neutral leptons (HNLs) from big bang nucleosynthesis. We show that even a small fraction of mesons present in the primeval plasma leads to the overproduction of primordial helium-4. This constrains the lifetime of HNLs to be ${\tau }_N<0.02\mathrm{s}$ for masses above the mass of the pion (as compared to 0.1 s reported previously). In combination with accelerator searches, this allows us to put a new lower bound on the HNL masses and define the “bottom line” for HNL searches at the future Intensity Frontier experiments.

We simulate neutrino-antineutrino oscillations caused by strong magnetic fields in dense matter. With the strong magnetic fields and large neutrino magnetic moments, Majorana neutrinos can reach flavor equilibrium. We find that the flavor equilibration of neutrino-antineutrino oscillations are sensitive to the values of the baryon density and the electron fraction inside the matter. The neutrino-antineutrino oscillations are suppressed in the case of the large baryon density in neutron- (proton)-rich matter. On the other hand, the flavor equilibration occurs when the electron fraction is close to 0.5 even in the large baryon density. From the simulations, we propose a necessary condition for the equilibration of neutrino-antineutrino oscillations in dense matter. We also study whether such a necessary condition is satisfied near the protoneutron star by using results of neutrino hydrodynamic simulations of core-collapse supernovae. In our explosion model, the flavor equilibration would be possible if the magnetic field on the surface of the protoneutron star were larger than ${10}^{14}\mathrm{G}$, which is the typical value of the magnetic fields of magnetars.

A class of noncanonical effective potentials is introduced allowing stable, radially symmetric, solutions to first order Bogomol’nyi equations for a real scalar field in a fixed spacetime background. This class of effective potentials generalizes those found previously by Bazeia, Menezes, and Menezes [Phys. Rev. Lett. 91, 241601 (2003)] for radially symmetric defects in a flat spacetime. Use is made of the “on-shell method” introduced by Atmaja and Ramadhan [Phys. Rev. D 90, 105009 (2014)] of reducing the second order equation of motion to a first order one, along with a constraint equation. This method and class of potentials admits radially symmetric, stable solutions for four dimensional static, radially symmetric spacetimes. Stability against radial fluctuations is established with a modified version of Derrick’s theorem, along with demonstrating that the radial stress vanishes. Several examples of scalar field configurations are given.

The strategy for assigning ${\mathbf{Z}}_{4R}$ parity in the string compactification is presented. For the visible sector, an anti-SU(5) [flipped-SU(5)] grand unification (GUT) model with three families is used to reduce the number of representations compared to the number in the minimal supersymmetric standard models. The SO(32) heterotic string is used to allow a large non-Abelian gauge group $\mathrm{SU}(N)$, $N\ge 9$, for the hidden sector such that the number of extra U(1) factors is small. A discrete subgroup of the gauge U(1)’s is defined as the ${\mathbf{Z}}_{4R}$ parity. Spontaneous symmetry breaking of anti-SU(5) GUT is achieved by the vacuum expectation values of two index antisymmetric tensor Higgs fields ${\mathbf{10}}_{+1}$ and ${\overline{\mathbf{10}}}_{-1}$ that led to our word “anti-SU(5).” In the illustrated example, the multiplicity 3 in one twisted sector allows the permutation symmetry $S_3$ that leads us to select the third family members and one MSSM pair of the Higgs quintets.

We generalize the dispersive approach to axial anomaly by A. D. Dolgov and V. I. Zakharov [Nucl. Phys. B27, 525 (1971).] to a non-Abelian case with arbitrary photon virtualites. We derive the anomaly sum rule for the singlet current and obtain the ${\pi }^0,\eta ,{\eta }^{\prime }\to \gamma {\gamma }^{*}$ transition form factors. Using them, we established the behavior of a nonperturbative gluon matrix element $⟨0|G\tilde{G}|\gamma {\gamma }^{*}(q^2)⟩$ in both spacelike and timelike regions. We found a significant contribution of the non-Abelian axial anomaly to the processes with one virtual photon, comparable to that of the electromagnetic anomaly. The duality between the axial and the vector channels was observed: the values of duality intervals and mixing parameters in the axial channel were related to vector resonances’ masses and residues. The possibility of a light pseudoscalar glueball-like state is conjectured.

We compute the renormalization and evolution of the soft-quark function that appears in the factorization theorem for Higgs-boson decays to two photons through a $b$-quark loop. Our computation confirms a conjecture by Liu, Mecaj, Neubert, Wang, and Fleming for the form of the renormalization and evolution of the soft-quark function in order ${\alpha }_s$. We also work out the analyticity structure of the soft-quark function by making use of light-front perturbation theory.

We perform a calculation of the one- and two-point correlation functions of energy density and axial charge deposited in the glasma in the initial stage of a heavy ion collision at finite proper time. We do this by describing the initial stage of heavy ion collisions in terms of freely evolving classical fields whose dynamics obey the linearized Yang-Mills equations. Our approach allows us to systematically resum the contributions of high momentum modes that would make a power series expansion in proper time divergent. We evaluate the field correlators in the McLerran-Venugopalan model using the glasma graph approximation, but our approach for the time dependence can be applied to a general four-point function of the initial color fields. Our results provide analytical insight into the preequilibrium phase of heavy ion collisions without requiring a numerical solution to the Yang-Mills equations.

If dark matter has mass lower than around 1 GeV, it will not impart enough energy to cause detectable nuclear recoils in many direct-detection experiments. However, if dark matter is upscattered to high energy by collisions with cosmic rays, it may be detectable in both direct-detection experiments and neutrino experiments. We report the results of a dedicated search for boosted dark matter upscattered by cosmic rays, using $\sim 14.6$ solar days of data from the PROSPECT reactor antineutrino experiment. We show that such a flux of upscattered dark matter would display characteristic diurnal sidereal modulation, and use this to set new experimental constraints on sub-GeV dark matter exhibiting large interaction cross sections.