Augmentations to the Euler-Heisenberg Lagrangian (QED one-loop effective action in homogeneous electromagnetic fields) under a constant background axial gauge are examined. Two special configurations admit an exact eigendecomposition, and hence effective action as a spectral sum, of the augmented Dirac operator: one with a magnetic field with chiral chemical potential, and the other with an electric field with spatial axial gauge, which resembles an emergent vorticity. An enhancement to Schwinger pair production is found for the latter, which is more fully analyzed using the worldline instanton formalism. There it is found the overall enhancement is due to the spatial axial gauge serving as a negative mass shift. Finally, we remark on the exactly solvable massless case for arbitrary electromagnetic and axial gauges.

The Higgs self-coupling measurement is quite essential for determining the shape of the Higgs potential and nature of the Higgs boson. We propose the di-Higgs plus jet final states at 100 TeV hadron colliders to increase the discovery sensitivity of the Higgs self-coupling at the low invariant mass region. With detector-level collider simulation, we find negative Higgs self-coupling would be disfavored beyond $2\sigma$ confidence level, and the allowed region of the Higgs self-coupling is [0.5, 1.7] with this channel only.

It has recently been argued that noisy intermediate-scale quantum computers may be used to optimize interpolating operator constructions for lattice quantum field theory (LQFT) calculations on classical computers. Here, two concrete realizations of the method are developed and implemented. The first approach is to maximize the overlap, or fidelity, of the state created by an interpolating operator acting on the vacuum state to the target eigenstate. The second is to instead minimize the energy expectation value of the interpolated state. These approaches are implemented in a proof-of-concept calculation in ($1+1$)-dimensions for a single-flavor massive Schwinger model to obtain quantum-optimized interpolating operator constructions for a vector meson state in the theory. Although fidelity maximization is preferable in the absence of noise due to quantum gate errors, it is found that energy minimization is more robust to these effects in the proof-of-concept calculation. This work serves as a concrete demonstration of how quantum computers in the intermediate term might be used to accelerate classical LQFT calculations.

We calculate the fully differential single-jet production in longitudinally polarized deep inelastic scattering (DIS) at next-to-next-to-leading-order (NNLO) accuracy, featuring both neutral-current and charged-current processes. The computation is done with the projection-to-Born method, using the next-to-leading-order dijet calculation and the NNLO DIS structure functions as its main ingredients. We also analyze its phenomenological consequences in the kinematics of the future Electron-Ion Collider.

We continue our investigation of the QCD dynamics in terms of the Curci-Ferrari effective Lagrangian, a deformation of the Faddeev-Popov one in the Landau gauge with a tree-level gluon mass term. In a previous work we have studied the dynamics of chiral symmetry breaking at the level of the quark propagator and, in particular, the dynamical generation of a constituent quark mass. In the present article, we study the associated Goldstone mode, the pion, and we compute the pion decay constant in the chiral limit. Our approach exploits the fact that the coupling (defined in the Taylor scheme) in the pure gauge sector is perturbative, as observed in lattice simulations which, together with a $1/N_c$-expansion, allows for a systematic, controllable approximation scheme in the low energy regime of QCD. At leading order, this leads to the well-known rainbow-ladder resummation. We study the region of parameter space of the model that gives physical values of the pion decay constant. This allows one to constrain the gluon mass parameter as a function of the coupling using a physically measured quantity.

We study gradient corrections to the transport equation for energetic light partons in dense QCD environments. In the diffusion limit, the transport dynamics is solely controlled by small-angle elastic scatterings, leading to transverse momentum broadening with respect to the parton’s initial direction. Such a parton propagation is usually considered in the limit of transversely homogeneous matter. The transport processes admit a classical description and the transverse spatial dependence of the medium properties emerges only through the jet quenching parameter. In this work, we show that a gradient expansion of the all-order evolution equation for the partonic Wigner function leads to an evolution equation in the Boltzmann-diffusion form only up to the leading order in transverse gradients. At the second order in gradients, the quantum corrections associated with nonlocal interactions give rise to a novel transport that can be implemented in Monte Carlo simulations. In addition, using our results, we compute the gradient corrections to the jet quenching parameter in inhomogeneous matter.

Topological defects attract much recent interest in high-energy and condensed matter physics, because they encode (noninvertible) symmetries and dualities. We study codimension-1 topological defects from a Hamiltonian point of view, with the defect location playing the role of “time.” We show that the Weinstein symplectic category governs topological defects and their fusion: Each defect is a Lagrangian correspondence, and defect fusion is their geometric composition. We illustrate the utility of these ideas by constructing S- and T-duality defects in string theory, including a novel topology-changing non-Abelian T-duality defect.

In this work, we show the robustness of uberholography and its associated quantum error correcting code against the breakdown of entanglement wedge in the presence of highly entropic mixed states in the bulk. We show that for Cantor-setlike erasure in the boundary in ${\mathrm{AdS}}_3/{\mathrm{CFT}}_2$, the code distance is independent of the mixed-state entropy in the bulk in the $m\to \infty$ limit. We also show that for a Sierpinski triangle shaped boundary subregion with fractal boundary erasures in ${\mathrm{AdS}}_4/{\mathrm{CFT}}_3$, bulk reconstruction is possible in the presence of highly entropic mixed states in the bulk in the large $m$ regime.

We explore the properties of a recently proposed background independent exact renormalization group approach to gauge theories and gravity. In the process we also develop the machinery needed to study it rigorously. The proposal comes with some advantages. It preserves gauge invariance manifestly, avoids introducing unphysical fields, such as ghosts and Pauli-Villars fields, and does not require gauge-fixing. However, we show that in the simple case of $SU(N)$ Yang-Mills it does not completely regularize the longitudinal part of vertex functions already at one loop, invalidating certain methods for extracting universal components. Moreover, we demonstrate a kind of no-go theorem: within the proposed structure, whatever choice is made for covariantization and cutoff profiles, the two-point vertex flow equation at one loop cannot be both transverse, as required by gauge invariance, and fully regularized.

The superradiant instabilities of Kerr-Newman black holes with charged or uncharged massive spin-0 fields are calculated analytically to the next-to-leading order in the limit of $\alpha \sim r_g\mu \ll 1$. A missing factor of $1/2$ in the previous leading-order result is identified. The next-to-leading order result has a compact form and is in good agreement with existing numerical calculations. The percentage error increases with $\alpha$, from a few percent for $\alpha \sim 0.1$ to about 50% for $\alpha \sim 0.4$. Massive neutral scalars too heavy to be produced with Kerr black hole superradiance may exist in the superradiant region of Kerr-Newman black holes.

In general, energy extraction methods such as the Penrose process and the magnetic Penrose process are thought to be reliant on the existence of an ergoregion. Inside an ergoregion, there are negative energy states that allow a particle to extract energy and escape to an observer at infinity. In this paper, we considered the electromagnetic field in the rotating Janis-Newman-Winicour (JNW) spacetime. This concept is feasible because an accretion disc forms an electromagnetic field around compact objects. After that, we briefly examine negative energy orbits and their significance in energy extraction. The ergoregion is absent in a rotating JNW geometry, but we show that the effective ergoregion is there. The change in a negative energy orbit concerning the magnetic field ($B$), spin parameter ($a$), and electric charge ($Q$) is analyzed. We find that the total energy extraction efficiency within this process can be around 60% for the rotating JNW naked singularity.

We present results from the new dendro-gr code. These include simulations of binary black hole mergers for mass ratios up to $q=16$. dendro-gr uses wavelet adaptive multiresolution to generate an unstructured grid adapted to the spacetime geometry together with an octree-based data structure. We demonstrate good scaling, improved convergence properties, and efficient use of computational resources. We validate the code with comparisons to lazev.

We show that infinite families of Galilean spin-3 symmetries in $2+1$ dimensions, which include higher-spin extensions of the Bargmann, Newton-Hooke, nonrelativistic Maxwell, and nonrelativistic AdS-Lorentz algebras, can be obtained as Lie algebra expansions of two different spin-3 extensions of the Nappi-Witten symmetry. These higher-spin Nappi-Witten algebras, in turn, are obtained by means of Inönü-Wigner contractions applied to suitable direct product extensions of $\mathfrak{s}\mathfrak{l}(3,\mathbb{R})$. Conversely, we show that the same result can be obtained by considering contractions of expanded $\mathfrak{s}\mathfrak{l}(3,\mathbb{R})$ algebras. The method can be used to define nonrelativistic higher-spin Chern-Simon gravity theories in $2+1$ dimensions in a systematic way.

We investigate the frame-dragging effect of the hairy Kerr spacetimes on the spin of a test gyro and accretion disk. First, we analyze Lense-Thirring (LT) precession frequency, geodetic precession frequency, and the general spin precession frequency of a test gyro attached to a stationary observer in the spacetime. We find that the black hole hair suppresses those precession frequencies in comparison with that which occurs in Kerr spacetime in general relativity. Moreover, using those frequencies as a probe, we differentiate the hairy Kerr black hole (BH) from naked singularity (NS). Specifically, as the observer approaches the central source along any direction, the frequencies grow sharply for the hairy Kerr BH, while for the hairy NS they are finite except at the ring singularity. Then, we investigate the quasiperiodic oscillations (QPOs) phenomena as the accretion disk approaches the hairy Kerr BH or NS. To this end, we analyze the bound circular orbits and their perturbations. We find that as the orbits approach the corresponding innermost stable circular orbit (ISCO), both LT precession frequency and periastron precession frequency behave differently in the hairy Kerr BH and NS. Additionally, the hairy parameters have significant effects on the two frequencies. We expect that our theoretical studies could shed light on astrophysical observations in distinguishing hairy theories from Einstein’s gravity, and also in distinguishing BH from NS in spacetime with hair.

We investigate two new observational perspectives in the context of torsional gravitational modification of general relativity, i.e., the $f(T)$ gravity: (i) We use Pantheon data of type Ia supernovae motivated by a time variation of the Newton’s constant on the supernovae distance modulus relation, and find that a joint analysis with baryon acoustic oscillations (BAO) and big bang nucleosynthesis (BBN), i.e., $\mathrm{Pantheon}+\mathrm{BAO}+\mathrm{BBN}$, provides constraints on the effective free parameter of the theory to be well compatible with the $\mathrm{\Lambda }\mathrm{CDM}$ prediction; (ii) We present the framework of $f(T)$ gravity at the level of linear perturbations with the phenomenological functions, namely the effective gravitational coupling $\mu$ and the light deflection parameter $\mathrm{\Sigma }$, which are commonly used to parametrize possible modifications of the Poisson equation relating the matter density contrast to the lensing and the Newtonian potentials, respectively. We use the available cosmic microwave background (CMB) datasets from the Planck 2018 release to constrain the free parameters of the $f(T)$ power-law gravity and $\mathrm{\Lambda }\mathrm{CDM}$ models. We find that CMB data, and its joint analyses with Pantheon and BAO data constrain the $f(T)$ power-law gravity scenario to be practically indistinguishable from the $\mathrm{\Lambda }\mathrm{CDM}$ model. We obtain the strongest limits ever reported on $f(T)$ power-law gravity scenario at the cosmological level.

In this paper we describe a new idea which may be relevant to the formation of galaxies via the infall of baryonic matter (BM) and dark matter (DM) onto a preexisting overdensity. While BM can under certain circumstances be captured by thermal processes, DM particles fly through a static overdensity without being captured. We propose a simple model for DM capture: if during the passage through it, the mass of the overdensity increases, then slow DM particles are captured by it, further increasing its mass, while faster particles slow down, transferring part of their energy to the galaxy. We estimate the minimum initial velocity of a particle required for a passage without capture through the center of the galaxy and derive a nonlinear equation describing the rate of galaxy mass increase. An analysis carried out using the ideas of catastrophes theory shows that if the increase in the mass of baryonic matter exceeds a certain threshold value, this can lead to a very intensive capture of dark matter. We speculate that this process may be associated on the one hand with the accretion of matter during the early stages of galaxy formation and, on the other hand, also later with the merger of galaxies. For the studied process to take place, the density of intergalactic DM must exceed some threshold value. Then the rate of increase in the mass of DM can be much higher than the one of baryonic matter. The capture sharply decreases after the DM density drops below the threshold value, e.g., due to the expansion of the Universe.

We propose possible properties of quantum gravity in de Sitter space, and find that they relate the value of the cosmological constant to parameters of the standard model. In de Sitter space we suggest (i) that the most sharply defined observables are obtained by scattering objects from the horizon and back to the horizon and (ii) that black holes of discrete charge are well defined states in the theory. For a black hole of minimal discrete electric charge, we therefore demand that a scattering process involving the black hole and a probe can take place within a Hubble time before evaporating away, so that the state of a discretely charged black hole is well defined. By imposing that the black hole’s charge is in principle detectable, which involves appreciably altering the state of a scattered electron, we derive a relation between the Hubble scale, or cosmological constant, and the electron’s mass and charge and order one coefficients that describe our ignorance of the full microscopic theory. This gives the prediction $\mathrm{\Lambda }\sim {10}^{-123\pm 2}{M}_{\mathrm{Pl}}^4$, which includes the observed value of dark energy. We suggest possible ways to test this proposal.

We present a complete halo model for mixed dark matter composed of cold dark matter (CDM) and ultralight axionlike particles (ULAs). Our model treats ULAs as a biased tracer of CDM, in analogy to treatments of massive neutrinos and neutral hydrogen. The model accounts for clustering of ULAs around CDM host halos, and fully models the cross correlations of both components. The model inputs include the ULA Jeans scale, and soliton density profile. Our model can be used to predict the matter power spectrum, $P(k)$, on nonlinear scales for subpopulations of ULAs across the mass range ${10}^{-33}\mathrm{eV}\le m\le {10}^{-21}\mathrm{eV}$, and can be calibrated against future mixed DM simulations to improve its accuracy. The mixed DM halo model also allows us to assess the importance of various approximations.