We investigate the effect of screening of the four-quarks contact interactions by the ring diagram at finite temperature and density in an effective chiral model inspired by QCD in the Coulomb gauge. As a consequence, a medium-dependent coupling naturally emerges which, in a class of chiral models, brings the chiral crossover temperature down to the value calculated in lattice QCD at low net-baryon density. Furthermore, it implies a stronger divergence of the chiral susceptibility at the critical point compared to the mean-field dynamics. At high densities, the screening induces a substantial instability region and its size depends on the regularization schemes. We discuss the properties of an effective potential for a class of models described by momentum-independent gap equations. In particular, we introduce the method to construct an approximate effective potential from the gap equations to determine the location of the first-order phase transition.

We systematically analyze the impact of dilatonic dynamics on Skyrme spheres, crystals, and branes. The effects of the dilatonic model parameters, encompassing different underlying near-conformal dynamics, on the macroscopic properties of skyrmions such as their mass and radius are discussed. For spheres and crystals we identify special values of the ratio of the decay constants for which the second order differential equations reduce to a solvable first order system. Additionally, in the case of the crystals, the dilaton presence spatially separates the baryon and isospin charge distributions. For branes, we show how the dilaton smooths out their configurations. Our results are expected to have wide implications from the study of near-conformal dynamics stemming from QCD-like theories to phenomenological investigations of nuclear matter in extreme regimes.

Charmed baryon decay plays an important role in studying the weak and strong interactions. Topological diagram is an intuitive tool for analyzing the dynamics of heavy hadron decays. In this work, we investigate the topological diagrams of charmed baryon antitriplet (${\mathcal{B}}_{c\overline{3}}$) decays into a light baryon octet (${\mathcal{B}}_8$) and a light meson ($M$). A one-to-one mapping between the topological diagram and the invariant tensor is established. The topological diagrams of the ${\mathcal{B}}_{c\overline{3}}\to {\mathcal{B}}_8^{S}M$ modes (where ${\mathcal{B}}_8^S$ and ${\mathcal{B}}_8^A$ are the $q_1\leftrightarrow q_2$ symmetric and antisymmetric octets) and the diagrams with a quark loop are presented for the first time. The completeness of topologies is confirmed by permutation. The linear relations of topologies are obtained by deriving the relation between the topological amplitudes constructed by the third- and second-rank octet tensors. It is found the topologies contributing to the ${\mathcal{B}}_{c\overline{3}}\to {\mathcal{B}}_8^{S}M$ modes can be determined by the topologies contributing to the ${\mathcal{B}}_{c\overline{3}}\to {\mathcal{B}}_8^{A}M$ modes, and vice versa. The equations of $SU(3)$ irreducible amplitudes decomposed by topologies are derived through two different intermediate amplitudes. However, the inverse solution does not exist since the number of topologies exceeds number of $SU(3)$ irreducible amplitudes. Applying this framework to the Standard Model, it is found there are thirteen independent $SU(3)$ irreducible amplitudes contributing to the ${\mathcal{B}}_{c\overline{3}}\to {\mathcal{B}}_{8}M$ decays. Among these, four amplitudes associated with three-dimensional operators are significant for $CP$ asymmetries. Considering the suppressions due to small Cabibbo-Kobayashi-Maskawa matrix elements and the Körner-Pati-Woo theorem, the branching fractions of charmed baryon decays are dominated by five $SU(3)$ irreducible amplitudes in the $SU(3{)}_F$ limit. Quark-loop diagrams could enhance the $U$-spin breaking effects and increase the branching fraction difference of two decay channels. Systematic measurements of branching fractions of the singly Cabibbo-suppressed modes could help identify promising channels for searching for $CP$ asymmetries in the charmed baryon sector.

In this paper, we show that the Cutkosky cutting rules are still valid term by term in the expansion in powers of $\kappa$ of the $\kappa$-deformed 1-loop correction to the propagator of the $\kappa$-deformed complex scalar field. We first present a general argument which relates each term in the expansion to a nondeformed amplitude containing additional propagators with mass $M>\kappa$. We then show the same thing more pragmatically, by reducing the singularity structure of the coefficients in the expansion of the $\kappa$-deformed amplitude, to the singularity structure of nondeformed loop amplitudes, by using algebraic and analytic identities. We will explicitly show this up to second order in $1/\kappa$, but the technique can be generalized to higher orders in $1/\kappa$. Both the abstract and the more direct approach easily generalize to different deformed theories. We will then compute the full imaginary part of the $\kappa$-deformed 1-loop correction to the propagator in a specific model, up to second order in the expansion in $1/\kappa$, highlighting the usefulness of the approach for the phenomenology of deformed models. This explicitly confirms previous qualitative arguments concerning the behavior of the decay width of unstable particles in the considered model.

The superpotential method is a reconstruction technique which has proven useful to build exact cosmological solutions. We here employ the superpotential method in order to reconstruct the features necessary for the inflaton potential to drive inflation and lead to the amplification of the curvature perturbations. Such an amplification, at wavelengths shorter than those observed in the cosmic microwave background, is necessary in order to have a significant formation of primordial black holes after inflation ends. The technique is applied to the cases of a minimally coupled inflaton, to the nonminimal coupling case and to $f(R)$ theories of gravity. For such theories, a model dependent analysis of the features leading to the scalar spectrum enhancement is also presented.

The goal of this paper is to analyze the effects of the matter fields in the evolution of the Bianchi IX cosmology close to the singularity. Although the dynamics of this model is very involved, asymptotically, as the singularity is approached, it can be well approximated as a succession of Bianchi I periods connected by quick bounces against potential walls. Moreover, in such limit, matter fields (excluding stiff matter) are known to be subdominant with respect to the anisotropies. Therefore, by performing an expansion around small volumes, and assuming that the matter contribution in this regime can be described as a barotropic perfect fluid with a linear equation of state, we obtain an approximate analytic solution of the dynamics. Then, we explicitly compute the form of the transition (Kasner) map that relates the pre- and postbounce Bianchi I periods including the leading matter effects. As an important conclusion, we observe that generically the presence of matter leads to a postbounce velocity with a lower deflection angle than in the vacuum case, and thus effectively increases the convex curvature of the potential walls. This effect may have important consequences in the chaotic nature of general relativity near spacelike singularities.

Coating noise is a consistently significant source of noise in high-precision gravitational wave measurements. In this paper, a model that quantifies the relationship between temperature noise and the optical path variation is proposed to analyze the thermo-optic noise of optical coating. There are two types of temperature-dependent noise—the traditional equilibrium thermal noise and the position noise introduced by the overall temperature fluctuation in the telescope load—that need to be considered for space gravitational wave detection satellites. In the current off-axis quad-mirror design, the incident angle of light from each mirror is very different, and the maximum incident angle reaches nearly 45°. The optical path noise of all-dielectric reflective coating will be more significant under the large incident angle. Metal reflective coating can effectively suppress the optical path noise caused by low-frequency temperature fluctuation, making them a viable alternative for space gravitational wave detectors. This paper provides a valuable reference for the selection of reflective coatings in space-based gravitational wave telescopes from the perspective of coating noise.

We complete the perturbative program for equilibrium thermodynamics of cosmological first-order phase transitions of gauge-Higgs theories that map into the (three-dimensional) superrenormalizable $\mathrm{SU}(2)+\mathrm{doublet}$ effective theory at high temperatures. To this end, we determine their finite-temperature effective potential at next-to-next-to-next-to-next-to-leading order (${\mathrm{N}}^4\mathrm{LO}$). The computation of the three-loop effective potential required to reach this order is also presented for U(1) gauge theories and is readily extendable to generic models in dimensionally reduced effective theories. Our ${\mathrm{N}}^4\mathrm{LO}$ result is the last perturbative order before confinement renders electroweak gauge-Higgs theories nonperturbative at four loops. By contrasting our analysis with nonperturbative lattice results, we find a remarkable agreement. As a direct application for predictions of gravitational waves produced by a first-order transition, our computation provides the final fully perturbative results for the phase transition strength and speed of sound.

We update earlier lattice results for the binding energies of the flavor antitriplet of strong-interaction-stable doubly bottom, $J^P=1^{+}$ tetraquarks, employing an extended sink construction which produces significantly improved ground-state effective-mass plateaus, as well as new, larger-volume ensembles which reduce possible finite-volume effects at lighter pion masses. The updated bindings are 115(17) MeV for the $I=0$ member of the antitriplet and 47(8) MeV for its $I=1/2$ partner. We also provide an update of our earlier study of the variable heavy mass dependence of binding in the $1^{+}$ channel and new results on this dependence for binding in the $0^{+}$ channel, accessible when the two heavy quarks have unequal masses. Implications of these results of potential relevance to experimental searches for signals of the production of doubly bottom tetraquarks and/or a possible bottom-charm partner of the $T_{cc}$ are also discussed.

Gravitational wave signals from extreme mass ratio inspirals are a key target for upcoming, space-based gravitational wave detectors. These systems are typically modeled as a distributionally forced Teukolsky equation, where the smaller black hole is treated as a Dirac delta distribution (i.e., a point-particle). Time-domain solvers often use regularization approaches that approximate the Dirac distribution. Unfortunately, such approaches often introduce small length scales (e.g., when the approximation is by a narrow Gaussian) and are a source of systematic error, especially near the smaller black hole. We describe a multidomain discontinuous Galerkin (DG) method for solving the distributionally forced $s=0$ Teukolsky equation that describes scalar fields evolving on a Kerr spacetime. To handle the Dirac delta, we expand the solution in spherical harmonics and recast the sourced Teukolsky equation as a first-order, one-dimensional symmetric hyperbolic system. This allows us to derive the method’s numerical flux to correctly account for the Dirac delta. As a result, our method achieves global spectral accuracy even at the source’s location. To connect the near field to future null infinity, we use the hyperboloidal layer method, allowing us to supply trivial outer boundary conditions and providing direct access to the far-field waveform. We document several numerical experiments where we test our method, including convergence tests against exact solutions, energy luminosities for circular orbits, the scheme’s superconvergence properties at future null infinity, and the late-time tail behavior of the scalar field. We also compare two systems that arise from different choices of the first-order reduction variables, finding that certain reasonable choices are numerically problematic in practice. The methods developed here may be beneficial when computing gravitational self-force effects, where the regularization procedure has been developed for the spherical harmonic modes and high accuracy is needed at the location of the Dirac delta.

We discuss a Weyl’s law for the quasinormal modes of black holes that recovers the structural features of the standard Weyl’s law for the eigenvalues of Laplacian-like operators in compact regions. Specifically, we propose that the asymptotics of the counting function $N(\omega )$ of quasinormal modes of ($d+1$)-dimensional black holes follows a power-law $N(\omega )\sim {\mathrm{Vol}}_d^{\mathrm{eff}}{\omega }^d$, with ${\mathrm{Vol}}_d^{\mathrm{eff}}$ an effective $d$-volume determined by the light-trapping properties of the black hole geometry. Concretely, the factorization ${\mathrm{Vol}}_d^{\mathrm{eff}}\sim (8\pi /\kappa )·{\mathrm{Vol}}_{d-1}^{\text{trapped}}$ makes apparent the two underlying structural ingredients, namely the (local) redshift effect controlled by the surface gravity $\kappa$ and the volume ${\mathrm{Vol}}_{d-1}^{\text{trapped}}$ of the (phase space) trapped set. In particular, this proposal extends the Weyl’s law proved by Dyatlov and Zworski for the counting of slowest decaying quasinormal modes, to include overtones. As an application, these Weyl’s laws could provide a probe into the effective spacetime dimensionality, upon the counting of sufficiently many quasinormal modes in the ringdown signal of binary black hole mergers.

Modifications to general relativity lead to effects in the spectrum of quasinormal modes of black holes. In this paper, we develop a parametrized formalism to describe deviations from general relativity in the Teukolsky equation, which governs linear perturbations of spinning black holes. We do this by introducing a correction to the effective potential of the Teukolsky equation in the form of a $1/r$ expansion controlled by free parameters. The method assumes that a small deviation in the effective potential induces a small modification in the spectrum of modes and in the angular separation constants. We isolate and compute the universal linear contribution to the quasinormal mode frequencies and separation constants in a set of coefficients and test them against known examples in the literature (massive scalar field, Dudley-Finley equation and higher-derivative gravity). We make the coefficients publicly available for relevant overtone, angular momentum, and azimuthal numbers of modes and different values of the black hole spin.

In the low-energy limit, the near region of a generic Kerr black hole has been conjectured to be holographically dual to a two-dimensional conformal field theory. In this paper, we consider a test object orbiting in the near region of a nonextremal Kerr black hole. We first couple it to a massless scalar field. The resulting scalar radiation at the horizon is computed from the perspectives of gravity and dual conformal field theory. Considering the influence of nonzero temperature, the agreement of both computations is found. Then, we generalize the analysis to the gravitational radiation and find agreement again. The agreement supports the conjectured holography and provides a potential theoretical tool for gravitational wave computations.

We study the late-time relaxation of a perturbed Schwarzschild black hole, driven by a source term representing an infalling particle in generic orbits. We consider quasicircular and eccentric binaries, dynamical captures and radial infalls, with orbital dynamics driven by an highly accurate analytical radiation reaction. After reviewing the description of the late-time behavior as an integral over the whole inspiral history, we derive an analytical expression that reproduces the slow relaxation (“tail”) observed in our numerical evolutions, obtained with a hyperboloidal compactified grid, for a given noncircular particle trajectory. We find this signal to be a superposition of an infinite number of power-laws, the slowest decaying term being Price’s law. Next, we use our model to explain the several orders-of-magnitude enhancement of tail terms for binaries in noncircular orbits, shedding light on recent unexpected results obtained in numerical evolutions. In particular, we show the dominant terms controlling the enhancement to be activated when the particle is far from the black hole, with small tangential and radial velocities soon before the plunge. As we corroborate with semianalytical calculations, this implies that for large eccentricities the tail amplitude can be correctly extracted even when starting to evolve only from the last apastron before merger. We discuss the implications of these findings on the extraction of late-time tail terms in nonlinear evolutions and possible observational consequences. We also briefly comment on the scattering scenario and on the connection with the soft graviton theorem.

The frozen star is a nonsingular, ultracompact object that, to an external observer, looks exactly like a Schwarzschild black hole, but with a different interior geometry and matter composition. The frozen star needs to be sourced by an extremely anisotropic fluid, for which the sum of the radial pressure and energy density is either vanishing or perturbatively small. Here, we show that this matter can be identified with the string fluid resulting from the decay of an unstable $D$-brane or a brane-antibrane system at the end of open-string tachyon condensation. The string fluid corresponds to flux tubes emanating from the center and ending at the Schwarzschild radius of the star. The effective Lagrangian for this fluid can be recast into a Born-Infeld form. When the fluid Lagrangian is coupled to that of Einstein’s gravity, the static, spherically symmetric solutions of the equations of motion are shown to be the same as those describing the frozen star model. Frozen stars can therefore be viewed as a gravitationally backreacted BIons model or that of gravitationally confined flux tubes. The Born-Infeld Lagrangian provides a complete set of equations that describe the dynamics of the frozen star in a generic state, which is not necessarily static nor spherically symmetric. Our framework therefore should allow a fully dynamical and out-of-equilibrium description of the frozen star model which will be relevant to gravitational waves observations of mergers of astrophysical black holes.

In this study, we explore the possibility of testing the no-hair theorem with gravitational waves from massive black hole binaries in the Laser Interferometer Space Antenna (LISA) frequency band. Based on its sensitivity, we consider LISA’s ability to detect possible deviations from general relativity (GR) in the ringdown. Two approaches are considered: an agnostic quasinormal mode (qnm) analysis and a method explicitly targeting the deviations from GR for given qnms. Both approaches allow us to find fractional deviations from GR as estimated parameters or by comparing the mass and spin estimated from different qnms. However, the estimated deviations may vary depending on whether we rely on prior knowledge of the source parameters from a premerger or inspiral-merger-ringdown analysis. Under some assumptions, the second approach targeting fractional deviations from GR allows us to recover the injected values with high accuracy and precision. We obtain 5%, 10% uncertainty on $\delta \omega ,\delta \tau$ respectively, for the (3, 3, 0) mode, and 3%, 17% for the (4, 4, 0) mode. As each approach constrains different features, we conclude combining both methods would be necessary to perform a better test. In this analysis, we also forecast the precision of the estimated deviation parameters for sources throughout the mass and distance ranges observable by LISA.

I obtain the effective Kähler potential at three-loop order for a general renormalizable supersymmetric theory containing only chiral supermultiplets. The three-loop contribution is remarkably simple, consisting of only four terms involving three distinct renormalized master integrals. In the case of the Wess-Zumino model with a single chiral superfield, I also obtain the effective auxiliary field potential at three-loop order, extending previous results at one-loop order. The method used is inferential, relying on existing knowledge of the ordinary scalar effective potential.

We present nonperturbative lattice calculations in the quenched approximation of the low-lying meson and baryon spectrum of the SU(4) gauge theory with fundamental fermion constituents. This theory is one instance of stealth dark matter, a class of strongly coupled theories, where the lowest mass stable baryon is the dark matter candidate. This work constitutes the first milestone in the program to study stealth dark matter self-interactions. Here, we focus on reducing excited state contamination in the single-baryon channel by applying the Laplacian Heaviside method, as well as projecting our baryon operators onto the irreducible representations of the octahedral group. We compare our resulting spectrum to previous work involving Gaussian smeared nonprojected operators and find good agreement with reduced statistical uncertainties. We also present the spectrum of the low-lying odd-parity baryons for the first time.

We report scale setting and hadronic properties for our new lattice QCD gauge configuration set (HAL-conf-2023). We employ ($2+1$)-flavor nonperturbatively improved Wilson fermions with stout smearing and the Iwasaki gauge action on a ${96}^4$ lattice, and generate configurations of 8000 trajectories at the physical point. We show the basic properties of the configurations such as the plaquette value, topological charge distribution and their autocorrelation times. The scale setting is performed by detailed analyses of the $\mathrm{\Omega }$ baryon mass. We calculate the physical results of quark masses, decay constants of pseudoscalar mesons and single hadron spectra in light quark sector. The masses of the stable hadrons are found to agree with the experimental values within a subpercent level.

The multiplicity distribution of charged particles produced in the central rapidity ($|\eta |<2.5$) region is calculated for the eikonal and the $U$-matrix unitarization schemes using the Abramovsky-Gribov-Kancheli (AGK) cutting rules and compared with the ATLAS 13 TeV data. The data favors the eikonal approach.