We explore the phenomenology of QCD axion and axionlike particle (ALP) dark matter production via misalignment during inflationary reheating. We investigate scenarios involving inflaton oscillating in a generic potential $\sim {\varphi }^n$, considering inflaton decay and annihilation for reheating. For low reheating temperatures, the parameter space leading to the correct relic abundance can be enlarged beyond the standard case. Depending on the type of inflaton-matter couplings and the value of $n$, we find that certain parts of the extended parameter space are already constrained by ADMX, CAPP, and MUSE experiments. Future haloscope experiments are expected to impose more stringent constraints. We highlight the potential to utilize axion experiments in constraining the dynamics of reheating.

In the context of $F(\varphi )R$ models of gravity, the conformal invariance of the curvature perturbation on uniform-field slices has been already demonstrated in several publications. In this work, we study the curvature perturbation $\mathcal{R}$ defined on hypersurfaces that comove with the effective fluid, whose energy-momentum tensor is covariantly conserved. We derive the expressions of $\mathcal{R}$ at first order in perturbations in the Jordan and Einstein frames and relate the two. Generically, $\mathcal{R}$ is not conformally invariant, but it is on sufficiently large scales during slow-roll inflation. Using our results, we also rederive the expressions for inflation observables in the Jordan frame.

Recent research has emphasized the benefits of accurately reconstructing the initial Lagrangian positions of biased tracers from their positions at a later time, to gain cosmological information. A weighted semidiscrete optimal transport algorithm can achieve the required accuracy, provided the late-time positions are known, with minimal information about the background cosmology. The algorithm’s performance relies on knowing the masses of the biased tracers, and depends on how one models the distribution of the remaining mass that is not associated with these tracers. We demonstrate that simple models of the remaining mass result in accurate retrieval of the initial Lagrangian positions, which we quantify using pair statistics and the void probability function. This is true even if the input positions are affected by redshift-space distortions. The most sophisticated models assume that the masses of the tracers, and the amount and clustering of the missing mass are known; we show that the method is robust to realistic errors in the masses of the tracers and remains so as the model for the missing mass becomes increasingly crude.

Recent gravitational-wave transient catalogs have used $p_{\text{astro}}$, the probability that a gravitational-wave candidate is astrophysical, to select interesting candidates for further analysis. Unlike false alarm rates, which exclusively capture the statistics of the instrumental noise triggers, $p_{\text{astro}}$ incorporates the rate at which triggers are generated by both astrophysical signals and instrumental noise in estimating the probability that a candidate is astrophysical. Multiple search pipelines can independently calculate $p_{\text{astro}}$, each employing a specific data reduction. While the range of $p_{\text{astro}}$ results can help indicate the range of uncertainties in its calculation, it complicates interpretation and subsequent analyses. We develop a statistical formalism to calculate a unified $p_{\text{astro}}$ for gravitational-wave candidates, consistently accounting for triggers from all pipelines, thereby incorporating extra information about a signal that is not available with any one single pipeline. We demonstrate the properties of this method using a toy model and by application to the publicly available list of gravitational-wave candidates from the first half of the third LIGO-Virgo-KAGRA observing run. Adopting a unified $p_{\text{astro}}$ for future catalogs would provide a simple and easy-to-interpret selection criterion that incorporates a more complete understanding of the strengths of the different search pipelines.

Top pairs produced at the Large Hadron Collider exhibit quantum entanglement of their spins near threshold and for boosted, central $t\overline{t}$ pairs. The entanglement is maintained between the decay products, in particular, between the top quark and the $W^{-}$ boson from the antiquark (or vice versa, between $\overline{t}$ and $W^{+}$) in certain kinematical regions. Therefore, $t\overline{t}$ production provides a rare opportunity to verify the spin entanglement between a fermion and a boson. The $tW$ entanglement can be probed at the $7\sigma$ level near threshold with run 2 data and at the $5\sigma$ level in the boosted region with the foreseen run 3 luminosity. In addition, the entanglement between the two $W$ bosons can be probed at the $4\sigma$ level at the LHC run 3.

Confirmed by the measurement of neutrino oscillations, neutrino mass is recognized as a genuine manifestation of physics beyond the Standard Model, while its originating mechanism remains a mystery. Moreover, the proper field-theory description of neutrinos, whether they are Majorana or Dirac type, must be linked to such a mechanism. The present work addresses the calculation, estimation, and analysis of one-loop contributions from virtual Majorana neutrinos, light and heavy as well, to the neutral gauge boson coupling $ZZZ$, which participates in $Z$-boson pair production from $e^{+}{e}^{-}$ collisions. This task is carried out in the framework defined by a seesaw variant in which light neutrinos remain massless at tree level, then becoming massive radiatively. The $ZZ{Z}^{*}$ coupling, with $Z^{*}$ an off-shell $Z$ boson, is defined by two form factors, namely, $f_4$, characterizing $CP$-odd effects, and $f_5$, which is $CP$-even. Constraints from the Large Hadron Collider on both of these quantities are currently $\mathcal{O}({10}^{-4})$. Our calculation yields $CP$-nonpreserving contributions to $ZZZ$, which are absent in the framework of the sole Standard Model. Our estimations show that the $f_4$ contribution might be as large as $\mathcal{O}({10}^{-7})$ for heavy-neutrino masses $\sim 1\mathrm{TeV}$. $CP$-even contributions $f_5$ are also generated, which are, in general, larger than their $CP$-odd counterparts. We estimate them to be as large as $\mathcal{O}({10}^{-4})$ at a center-of-mass energy of 500 GeV, in $e^{+}{e}^{-}$ collisions.

We investigate the possibility of observable proton decay within the improved missing doublet model (IMDM75), which utilizes a Higgs in 75 representation for SU(5) gauge symmetry breaking. The realization of observable proton decay in IMDM75 is made feasible primarily due to chirality nonflipping color-triplet mediation, while chirality flipping mediation is adequately suppressed. Our predictions suggest a range of proton lifetimes between ${10}^{34}$ and ${10}^{36}\mathrm{yr}$, which can be observed in upcoming experiments such as Hyper-K and DUNE, for a corresponding range of color-triplet mass parameter $M_T$ in the order of ${10}^{11}–{10}^{14}\mathrm{GeV}$. IMDM75 is shown to offer unique predictions for branching ratios when compared to other grand unified theory models. Finally, a realization of successful gauge coupling unification is achieved, even with the presence of particles at intermediate scales.

The Collins-Soper (CS) kernel is a nonperturbative function that characterizes the rapidity evolution of transverse-momentum-dependent parton distribution functions (TMDPDFs) and wave functions. In this paper, we calculate the CS kernel for pion and proton targets and for quasi-TMDPDFs of leading and next-to-leading power. The calculations are carried out on the CLS ensemble H101 with dynamical $N_f=2+1$ clover-improved Wilson fermions. Our analyses demonstrate the consistency of different lattice extractions of the CS kernel for mesons and baryons, as well as for twist-two and twist-three operators, even though lattice artifacts could be significant. This consistency corroborates the universality of the lattice-determined CS kernel and suggests that a high-precision determination of it is in reach.

The photoprodution of doubly heavy baryon (${\mathrm{\Xi }}_{cc},{\mathrm{\Xi }}_{bb},{\mathrm{\Xi }}_{bc}$) is investigated in the context of future high-energy and high-luminosity $e^{+}{e}^{-}$ colliders. The study incorporates two sources of initial photons, namely the laser back-scattering photon and the Weizäcker-Williams approximation photon. Alongside the direct photoproduction via the subprocess $\gamma +\gamma \to {\mathrm{\Xi }}_{Q{Q}^{\prime }}+\overline{Q}+{\overline{Q}}^{\prime }$ ($Q^{(\prime )}=c$, $b$), the resolved photoproduction channels are specifically considered, encompassing the subprocesses $\gamma +g\to {\mathrm{\Xi }}_{Q{Q}^{\prime }}+\overline{Q}+{\overline{Q}}^{\prime }$, $g+g\to {\mathrm{\Xi }}_{Q{Q}^{\prime }}+\overline{Q}+{\overline{Q}}^{\prime }$, and $q+\overline{q}\to {\mathrm{\Xi }}_{Q{Q}^{\prime }}+\overline{Q}+{\overline{Q}}^{\prime }$ with $q=u$, $d$, $s$. Within the framework of nonrelativistic QCD, two $[cc(bb)]$-diquark configurations, ${}_{\overline{\mathbf{3}}}[{{}^{3}S}_1]$ and ${}_{\mathbf{6}}[{{}^{1}S}_0]$, and four $(bc)$-diquark configurations, $(bc){}_{\overline{\mathbf{3}}}[{{}^{3}S}_1]$, $(bc){}_{\mathbf{6}}[{{}^{1}S}_0]$, $(bc){}_{\mathbf{6}}[{{}^{3}S}_1]$, and $(bc){}_{\overline{\mathbf{3}}}[{{}^{1}S}_0]$, are considered in the calculations. Numerical results show that the single resolved photoproduction processes provide dominant contributions under certain collision configuration. At the future $e^{+}{e}^{-}$ colliders, the doubly heavy baryon generated via the photoproduction mechanism is promisingly observable and can be well-studied.

Reported here are transverse single-spin asymmetries ($A_N$) in the production of charged hadrons as a function of transverse momentum ($p_T$) and Feynman-$x$ ($x_F$) in polarized $p^{\uparrow }+p$, $p^{\uparrow }+\mathrm{Al}$, and $p^{\uparrow }+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$. The measurements have been performed at forward and backward rapidity ($1.4<|\eta |<2.4$) over the range of $1.5\mathrm{GeV}/c<p_T<7.0\mathrm{GeV}/c$ and $0.04<|x_F|<0.2$. A nonzero asymmetry is observed for positively charged hadrons at forward rapidity ($x_F>0$) in $p^{\uparrow }+p$ collisions, whereas the $p^{\uparrow }+\mathrm{Al}$ and $p^{\uparrow }+\mathrm{Au}$ results show smaller asymmetries. This finding provides new opportunities to investigate the origin of transverse single-spin asymmetries and a tool to study nuclear effects in $p+A$ collisions.

We examine aspects of locality in perturbative quantum gravity and how information can be localized in subregions. In the framework of $\mathrm{AdS}/\mathrm{CFT}$, we consider the algebra of single-trace operators defined in a short time band. We conjecture that, if the state has large energy variance, then this algebra will have a commutant in the $1/N$ expansion. We provide evidence for this by identifying operators that commute with the conformal field theory Hamiltonian to all orders in $1/N$, thus resolving an apparent tension with the gravitational Gauss law. The bulk interpretation is that these operators are gravitationally dressed with respect to features of the state rather than the boundary. We comment on observables in certain black hole microstates and the gravitational dressing in the island proposal.

In this study, we employ a modified soft-wall holographic model with four flavors to investigate the meson spectra, decay constants, electromagnetic form factors, and charge radius of various mesons. We obtain the spectra for vector, axial vector, and pseudoscalar mesons. Decay constants are calculated and compared with experimental and lattice QCD data. The pion and kaon electromagnetic form factors are compared with the experimental data, and a good agreement is achieved for the kaon at low $Q^2$. For the charmed mesons, the electromagnetic form factors of the $D$ and $D_s$ and electric form factors of the $D^{*}$ and $D_s^{*}$ are well consistent with the lattice QCD data. Moreover, the electric, magnetic, and quadrupole form factors are predicted for the $\rho$, $K^{*}$, $a_1$, $K_1$, $D_1$, and $D_{s1}$ mesons. Furthermore, the charge radius of the vector, axial vector, and pseudoscalars, including the strange and charmed mesons, are computed.

We prove novel far-from-equilibrum bounds on conformal field theories, upper bounding the growth rate of entanglement entropy in spatially uniform states. When equal-time correlators and Wilson loops are computed by geodesics and world sheets, we also bound the growth rate of these. Example applications include lower bounds on thermalization times or the time it takes to achieve deconfinement. Our bounds are proven for holographic conformal field theories at strong coupling and large–$N$, but we provide evidence that they are valid independent of these assumptions. In two dimensions, our results prove a conjectured bound on entanglement growth by Liu and Suh for a large class of states. We also derive bounds on spatial derivatives of correlation measures. From a gravitational perspective, our results constitute new lower bounds on the mass of asymptotically AdS spacetimes with planar symmetry, strengthening the positive mass theorem for these spacetimes. We also derive novel relations in $\mathrm{AdS}/\mathrm{CFT}$ relating various geometric features directly to entanglement entropy derivatives. For example, we show that conformal field theory entanglement growth corresponds to bulk matter falling deeper into the bulk.

We show that the recently proposed equations for holomorphic sector of higher-spin theory in $d=4$, also known as chiral, can be naturally extended to describe interacting symmetric higher-spin gauge fields in any dimension. This is achieved with the aid of Vasiliev’s off shell higher-spin algebra. The latter contains ideal associated to traces that has to be factored out in order to set the equations on shell. To identify the ideal in interactions we observe the global $sp(2)$ that underlies it to all orders. The $sp(2)$ field dependent generators are found in closed form and appear to be remarkably simple. The traceful higher-spin vertices are analyzed against locality and shown to be all-order space-time spin-local in the gauge sector, as well as spin-local in the Weyl sector. The vertices are found manifestly in the form of curious integrals over hypersimplices. We also extend to any $d$ the earlier observed in $d=4$ higher-spin shift symmetry known to be tightly related to spin-locality.

Flavored modular differential equations sometimes arise from null states or their descendants in a chiral algebra with continuous flavor symmetry. In this paper we focus on Kac-Moody algebras ${\widehat{\mathfrak{g}}}_k$ that contain a level-four null state $|{\mathcal{N}}_T⟩$ which implements the nilpotency of the Sugawara stress tensor. We study the properties of the corresponding flavored modular differential equations, and show that the equations exhibit almost covariance under modular $S$-transformation, connecting null states and their descendants at different levels. The modular property of the equations fixes the structure of $\mathfrak{g}$ and the level $k$, as well as the flavored characters of all the highest weight representations. Shift property of the equations can generate nonvacuum characters starting from the vacuum character.

The propagation of gravitational waves can reveal fundamental features of the structure of spacetime. For instance, differences in the propagation of gravitational-wave polarizations would be a smoking gun for parity violations in the gravitational sector, as expected from birefringent theories like Chern-Simons gravity. Here we look for evidence of amplitude birefringence in the third catalog of detections by the Laser Interferometer Gravitational Wave Observatory and Virgo through the use of birefringent templates inspired by dynamical Chern-Simons gravity. From 71 binary-black-hole signals, we obtain the most precise constraints on gravitational-wave amplitude birefringence yet, measuring a birefringent attenuation of $\kappa =-0.019_{-0.029}^{+0.038}{\mathrm{Gpc}}^{-1}$ at 100 Hz with 90% credibility, equivalent to a parity-violation energy scale of $M_{\mathrm{PV}}\gtrsim 6.8\times {10}^{-21}\mathrm{GeV}$.

The axial symmetric Finslerian extension of a Schwarzschild spacetime is a generalization of Schwarzschild spacetime. It will return to Schwarzschild spacetime while the Finslerian parameter $\epsilon =0$. Closed orbits are an important geometrical subject in mathematics that will help us to understand the physical properties of black holes in a strong gravitational region. The closed orbits of the axial symmetric Finslerian extension of a Schwarzschild black hole have been investigated in this paper. We have found that one necessary condition for the orbits of a Finslerian black hole to be closed is that the Finslerian parameter $\epsilon$ be rational. The numerical results of closed orbits of a Finslerian black hole are shown. They confirm our conclusion of the existence conditions of closed orbits.

In its canonical formulation, general relativity is subject to gauge transformations that are equivalent to space-time coordinate changes of general covariance only when the gauge generators, given by the Hamiltonian and diffeomorphism constraints, vanish. Since the specific form taken by Poisson brackets of the constraints and of the gauge transformations and equations of motion they generate is important for general covariance to be realized, modifications of the canonical theory, suggested for instance by approaches to quantum gravity, are not guaranteed to be compatible with the existence of a covariant space-time line element. This caveat applies even if the modification preserves the number of independent gauge transformations and the modified constraints remain first class. Here, a complete derivation of covariance conditions, regained from the canonical constraints without assuming that space-time has its classical structure, is presented and applied in detail to spherically symmetric vacuum models. As a broad application, the presence of structure functions in the constraint brackets plays a crucial role, which in an independent analysis has recently been shown to lead to higher algebraic structures in hypersurface deformations given by an $L_{\infty }$ bracket. The physical analysis of a related feature presented here demonstrates that, at least within the spherically symmetric setting, new theories of modified gravity are possible that are not of higher-curvature form.

We consider accretion of charged test matter by rotating, magnetic black holes and discuss a number of aspects in which the interaction of the angular momentum contained in the electromagnetic field and the spin of the hole plays a fundamental role. First, we argue that such a black hole tends to lose its angular momentum by accreting charges while remaining globally neutral. Then, we show that accretion can happen in a superradiant manner via an enhanced Penrose process. In particular, we find that the regions from which energy and angular momentum can be extracted contain the axis of rotation and, in some cases, consist of floating bubbles disconnected from the black hole itself. Finally, we address the question of whether extremal dyonic rotating black holes can be overcharged or overspun via accretion of arbitrary matter and prove that this cannot happen if the null-energy condition holds. We conclude by discussing some future research directions.