Current gravitational-wave observations set the most stringent bounds on the abundance of primordial black holes (PBHs) in the solar mass range. This constraint, however, inherently relies on the merger rate predicted by PBH models. Previous analyses have focused mainly on two binary formation mechanisms: early Universe assembly out of decoupling from the Hubble expansion and dynamical capture in present-day dark matter structures. Using reaction rates of three-body processes studied in the astrophysical context, we show that, under conservative assumptions, three-body interactions in PBH halos efficiently produce binaries. Those binaries form at high redshift in Poisson-induced PBH small-scale structures and a fraction is predicted to coalesce and merge within the current age of the Universe, at odds with the dynamical capture scenario where they merge promptly. In general, we find that this channel predicts rates comparable to the dynamical capture scenario. However, binaries formed from three-body interactions do not significantly contribute to the overall PBH merger rate unless PBHs made up a dominant fraction of the dark matter above the solar mass range, a scenario that is ruled out by current constraints. Our results support strong bounds on the PBH abundance in the stellar mass range derived from Laser Interferometer Gravitational-Wave Observatory/Virgo/KAGRA observations. Finally, we show that both dynamical channels are always subdominant compared to early Universe assembly for PBH mergers in the asteroid mass range, while we expect it to become relevant in scenarios where PBHs are initially strongly clustered.

We use ten years of publicly available IceCube data to investigate the correlations between high-energy neutrinos and various Fermi-LAT gamma-ray samples. This work considers the following gamma-ray samples: the third Fermi-LAT catalog of high-energy sources (3FHL), $>100\mathrm{GeV}$ Fermi-LAT events, the LAT 12-year source catalog (4FGL), the fourth catalog of active galactic nuclei (4LAC), and subsets of these samples. For each sample, both a single-source analysis and a stacking analysis are performed. We find no indication that the sources in these samples produce significant high-energy neutrinos. From the null search results, we infer that each source population can produce no more than $\sim 2.5\%–36\%$ (at the 95% confidence level, for a spectral index of $-2.5$) of the IceCube’s diffuse neutrino flux. Since we are using a larger (ten-year) dataset of IceCube neutrinos, the constraints are improved by a factor of $\sim 2$ compared to those based on three years of data.

Entanglement generation by Newtonian gravitational potential between objects has been widely discussed to reveal the quantum nature of gravity. In this paper, we perform a quantum field theoretical analysis of a slightly modified version of the gedanken experiment by Mari and co-workers [A. Mari et al., Sci. Rep. 6, 22777 (2016).]. We show that decoherence due to the presence of a detector propagates with the speed of light in terms of a retarded Green’s function, as it should be consistent with causality of relativistic field theories. The quantum nature of fields, such as quantum fluctuations or emission of gravitons expressed in terms of the Keldysh Green’s function also play important roles in the mechanism of decoherence due to on-shell particle creation. We also discuss the trade-off relation between the visibility of the interference and the distinguishability of the measurement, known as the particle-wave duality, in our setup.

We consider the anomalous magnetic moment of the muon $a_{\mu }$, which shows a significant deviation from the Standard Model expectation given the recent measurements at Fermilab and Brookhaven National Lab (BNL). We focus on Standard Model effective field theory (SMEFT) with the aim to identify avenues for the upcoming LHC runs and future experiments such as MUonE. To this end, we include radiative effects to $a_{\mu }$ in SMEFT to connect the muon anomaly to potentially interesting searches at the LHC, specifically Higgs decays into muon pairs and such decays with resolved photons. Our investigation shows that, similar to results for concrete UV extensions of the Standard Model, the Fermilab/BNL result can indicate strong coupling within the EFT framework and $a_{\mu }$ is increasingly sensitive to a single operator direction for high scale UV completions. In such cases, there is some complementarity between expected future experimental improvements, yet with considerable statistical challenges to match the precision provided by the recent $a_{\mu }$ measurement.

The symmetry breaking of grand unified gauge groups in the early Universe often leaves behind relic topological defects such as cosmic strings, domain walls, or monopoles. For some symmetry breaking chains, hybrid defects can form where cosmic strings attach to domain walls or monopoles attach to strings. In general, such hybrid defects are unstable, with one defect “eating” the other via the conversion of its rest mass into the other’s kinetic energy and, subsequently, decaying via gravitational waves. In this work, we determine the gravitational wave spectrum from 1) the destruction of a cosmic string network by the nucleation of monopoles which cut up and “eat” the strings, 2) the collapse and decay of a monopole-string network by strings that eat the monopoles, 3) the destruction of a domain wall network by the nucleation of string-bounded holes on the wall that expand and eat the wall, and 4) the collapse and decay of a string-bounded wall network by walls that eat the strings. We call the gravitational wave signals produced from the eating of one topological defect by another “gravitational wave gastronomy.” We find that the four gravitational wave gastronomy signals considered yield unique spectra that can be used to narrow down the $SO(10)$ symmetry breaking chain to the Standard Model and the scales of symmetry breaking associated with the consumed topological defects. Moreover, the systems we consider are unlikely to have a residual monopole or domain wall problem.

In this work, we perform a systematic study of possible molecular states composed of two charmed baryons including hidden-charm systems ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Lambda }}}_c$, ${\mathrm{\Sigma }}_c^{(*)}{\overline{\mathrm{\Sigma }}}_c^{(*)}$, and ${\mathrm{\Lambda }}_c{\overline{\mathrm{\Sigma }}}_c^{(*)}$, and corresponding double-charm systems ${\mathrm{\Lambda }}_c{\mathrm{\Lambda }}_c$, ${\mathrm{\Sigma }}_c^{(*)}{\mathrm{\Sigma }}_c^{(*)}$, and ${\mathrm{\Lambda }}_c{\mathrm{\Sigma }}_c^{(*)}$. With the help of the heavy quark chiral effective Lagrangians, the interactions are described with $\pi$, $\rho$, $\eta$, $\omega$, $\varphi$, and $\sigma$ exchanges. The potential kernels are constructed, and inserted into the quasipotential Bethe-Salpeter equation. The bound states from the interactions considered is studied by searching for the poles of the scattering amplitude. The results suggest that strong attractions exist in both hidden-charm and double-charm systems considered in the current work, and bound states can be produced in most of the systems. More experimental studies about these molecular states are suggested though the nucleon-nucleon collision at LHC and nucleon-antinucleon collision at $\overline{\mathrm{P}}\mathrm{ANDA}$.

The role of slow out-of-equilibrium modes (OEMs), introduced to extend the validity of hydrodynamics near the QCD critical point on the power spectrum of dynamical density fluctuations has been studied. We have used the equation of motion of slow modes for the situation when the extensive nature of thermodynamics is not altered due to the introduction of the OEM. We find that the extensivity condition puts an extra constraint on the coupling of OEM with the 4-divergence of velocity. The dynamic structure factor [${\mathcal{S}}_{nn}(\mathit{k},\omega )$] in the presence of the OEM shows four Lorentzian peaks asymmetrically positioned about $\omega (\text{frequency})=0$, whereas it shows three well-known Lorentzian peaks in the absence of the OEM. We find that the asymmetric peaks originate due to the coupling of the OEM with the hydrodynamic modes. It is also shown that the OEM has smaller effects on ${\mathcal{S}}_{nn}(\mathit{k},\omega )$ evaluated within the scope of the first-order hydrodynamics (relativistic Navier-Stokes). The width of the Rayleigh peak is reduced in the presence of OEM, indicating the reduction of the decay rate of the fluctuations connected to the slowing down, a well-known characteristic of the critical end point.

Recently the CDF Collaboration at the Tevatron reported a significant discrepancy between the direct measurement of the $W$-boson mass and its Standard Model (SM) prediction based on electroweak precision tests (EWPTs). In this paper, we explore the potential origin of this discrepancy from physics beyond the SM. Explicitly, we work on a set of six-dimensional operators in the SM effective field theory (SMEFT) which are relevant to the EWPTs. By fitting to the data, we demonstrate that an upward shift in $m_W$ is driven by the operator ${\mathcal{O}}_T=\frac{1}{2}(H^{†}{\overleftrightarrow{D}}_{\mu }H{)}^2$ with a coefficient $c_T(\mathrm{TeV}/\mathrm{\Lambda }{)}^2\gtrsim 0.01$. This suggests that the new physics scale favored by the CDF data should be multiple TeV for tree-level effects and sub-TeV for loop-level effects. One simple example is to introduce a hypercharge-free electroweak triplet scalar which can raise the $c_T$ value at tree level. We also study the potential to further test the relevant SMEFT by measuring Higgs-coupling, $m_W$, and other EWPTs at future circular $e^{-}{e}^{+}$ colliders.

Based on a sample of $(10.09\pm 0.04)\times {10}^9$ $J/\psi$ events collected with the BESIII detector operating at the BEPCII storage ring, a partial wave analysis of the decay $J/\psi \to \gamma \eta {\eta }^{\prime }$ is performed. An isoscalar state with exotic quantum numbers $J^{PC}=1^{-+}$, denoted as ${\eta }_1(1855)$, has been observed for the first time with statistical significance larger than $19\sigma$. Its mass and width are measured to be $(1855\pm 9_{-1}^{+6})\mathrm{MeV}/c^2$ and $(188\pm {18}_{-8}^{+3})\mathrm{MeV}$, respectively. The first uncertainties are statistical and the second are systematic. The product branching fraction $\mathcal{B}(J/\psi \to \gamma {\eta }_1(1855))\mathcal{B}({\eta }_1(1855)\to \eta {\eta }^{\prime })$ is measured to be $(2.70\pm {0.41}_{-0.35}^{+0.16})\times {10}^{-6}$. In addition, an upper limit on the ratio of branching fractions $\mathcal{B}(f_0(1710)\to \eta {\eta }^{\prime })/\mathcal{B}(f_0(1710)\to \pi \pi )$ is determined to be $1.61\times {10}^{-3}$ at 90% confidence level, which lends support to the hypothesis that the $f_0(1710)$ has a large glueball component.

We find analytic solutions of hyperbolic black holes with scalar hair in anti–de Sitter (AdS) space, and they do not have spherical or planar counterparts. The system is obtained by taking a neutral limit of an Einstein-Maxwell-dilaton system whose special cases are maximal gauged supergravities, while the dilaton is kept nontrivial. There are phase transitions between these black holes and the hyperbolic Schwarzschild-AdS black hole. We discuss two $\mathrm{AdS}/\mathrm{CFT}$ applications of these hyperbolic black holes. One is phase transitions of holographic Rényi entropies, and the other is phase transitions of quantum field theories in de Sitter space. In addition, we give a C-metric solution as a generalization of the hyperbolic black holes with scalar hair.

In a recent work Qiao and Li [Phys. Rev. D 106, L021501 (2022)], a new geometric approach is proposed to obtain the photon sphere (circular photon orbit) and the black hole shadow radius. In this approach, photon spheres and the black hole shadow radius are determined using geodesic curvature and Gaussian curvature in the optical geometry of black hole spacetimes. However, the calculations in Qiao and Li only restricted to a subclass of static and spherically symmetric black holes with spacetime metric $g_{tt}·g_{rr}=-1$, $g_{\theta \theta }=r^2$ and $g_{\varphi \varphi }=r^2{\sin }^2\theta$. In this work, we extend this approach to more general spherically symmetric black holes (with spacetime metric $d{s}^2=g_{tt}d{t}^2+g_{rr}d{r}^2+g_{\theta \theta }d{\theta }^2+g_{\varphi \varphi }d{\varphi }^2$). Furthermore, it can be proved that our results from the geometric approach are completely equivalent to those from conventional approach based on effective potentials of test particles.

We demonstrate the application of the YOLOv5 model, a general purpose convolution-based object detection model, in the task of detecting binary neutron star coalescence events from gravitational-wave data of current generation interferometer detectors. We also present a thorough explanation of the synthetic data generation and preparation tasks based on approximant waveform models used for the model training, validation and testing steps. Using this approach, we achieve mean average precision [0.50] values of 0.945 for a single class validation dataset and as high as 0.978 for test datasets. Moreover, the trained model is successful in identifying the GW170817 event in the LIGO H1 detector data. The identification of this event is also possible for the LIGO L1 detector data with an additional preprocessing step, without the need of removing the large glitch in the final stages of the inspiral. The detection of the GW190425 event is less successful, which attests to performance degradation with the signal-to-noise ratio. Our study indicates that the YOLOv5 model is an interesting approach for first-stage detection alarm pipelines.

Extreme mass ratio inspirals (EMRIs)—systems with a compact object orbiting a much more massive (e.g., Galactic Center) black hole—are of interest as a new probe of the environments of galactic nuclei, and their waveforms are a precision test of the Kerr metric. This work focuses on the effects of an external perturbation due to a third body around an EMRI system. This perturbation will affect the orbit most significantly when the inner body crosses a resonance with the outer body, and results in a change of the conserved quantities (energy, angular momentum, and Carter constant) or equivalently of the actions, which results in a subsequent phase shift of the waveform that builds up over time. We present a general method for calculating the changes in action during a resonance crossing, valid for generic orbits in the Kerr spacetime. We show that these changes are related to the gravitational waveforms emitted by the two bodies (quantified by the amplitudes of the Weyl scalar ${\psi }_4$ at the horizon and at $\infty$) at the frequency corresponding to the resonance. This allows us to compute changes in the action variables for each body, without directly computing the explicit metric perturbations, and therefore we can carry out the computation by calling an existing black hole perturbation theory code. We show that our calculation can probe resonant interactions in both the static and dynamical limit. We plan to use this technique for future investigations of third-body effects in EMRIs and their potential impact on waveforms for LISA.

In this paper we present several set of solutions of static and spherically symmetric solitonic boson stars. Each set is characterized by the value of $\sigma$ that defines the solitonic potential in the complex scalar field theory. The main features peculiar to this potential occur for small values of $\sigma$, but for which the equations become so stiff as to pose numerical challenges. By solving the full system of field equations without simplifications we build the sets for decreasing $\sigma$ values and show how they change their behavior in the parameter space, giving special attention to the region where thin-wall configurations dwell. The validity of the thin-wall approximation is explored as well as the possibility of the solution sets being discontinuous. We investigate five different possible definitions of a radius for boson stars and employ them to calculate the compactness of each solution in order to assess how different the outcomes might be.

The neutron star-black hole binary (NSBH) system has been considered one of the promising detection candidates for ground-based gravitational-wave (GW) detectors such as LIGO and Virgo. The tidal effects of neutron stars (NSs) are imprinted on the GW signals emitted from NSBHs as well as binary neutron stars. The NS tidal deformability (${\lambda }_{\mathrm{NS}}$) was successfully measured by the binary neutron star signal GW170817 but could not be constrained in the analysis of the two NSBH signals GW200105 and GW200115 due to the low signal-to-noise ratio. In this work, we study how accurately the parameter ${\lambda }_{\mathrm{NS}}$ can be measured in GW parameter estimation for NSBH signals. We set the parameter range for the NSBH sources to $[4M_{\odot },10M_{\odot }]$ for the black hole mass, $[1M_{\odot },2M_{\odot }]$ for the NS mass, and $[-0.9,0.9]$ for the dimensionless black hole spin. For realistic populations of sources distributed in different parameter spaces, we calculate the measurement errors of ${\lambda }_{\mathrm{NS}}$ (${\sigma }_{{\lambda }_{\mathrm{NS}}}$) using the Fisher matrix method. In particular, we perform a single-detector analysis using the advanced LIGO and the Cosmic Explorer detectors and a multidetector analysis using the 2G (advanced LIGO-Hanford, advanced LIGO-Livingstone, advanced Virgo, and KAGRA) and the 3G (Einstein Telescope and Cosmic Explorer) networks. We show the distribution of ${\sigma }_{{\lambda }_{\mathrm{NS}}}$ for the population of sources as a one-dimensional probability density function. Our result shows that the probability density function curves are similar in shape between advanced LIGO and Cosmic Explorer, but Cosmic Explorer can achieve $\sim 15$ times better accuracy overall in the measurement of ${\lambda }_{\mathrm{NS}}$. In the case of the network detectors, the probability density functions are maximum at ${\sigma }_{{\lambda }_{\mathrm{NS}}}\sim 130$ and $\sim 4$ for the 2G and the 3G networks, respectively, and the 3G network can achieve $\sim 10$ times better accuracy overall. Specifically, we investigate the distribution of ${\sigma }_{{\lambda }_{\mathrm{NS}}}$ for ${10}^3$ Monte Carlo sources in our parameter range with the NS mass fixed to $m_2=1.4M_{\odot }$, and the result shows that if the sources are located at $d_L\simeq 100\mathrm{Mpc}$, the parameter estimation results for $\sim 80\%$ of the sources can distinguish between the theoretical EOS models at the 1–$\sigma$ level, using the 3G network. Additionally, we demonstrate that our probability density function results are almost unaffected by different choices of the true value of ${\lambda }_{\mathrm{NS}}$.

We construct higher-dimensional generalizations of the Eguchi-Hanson gravitational instanton in the presence of higher-curvature deformations of general relativity. These spaces are solutions to Einstein gravity supplemented with the dimensional extension of the quadratic Chern-Gauss-Bonnet invariant in arbitrary even dimension $D=2m\ge 4$, and they are constructed out of nontrivial fibrations over ($2m-2$)-dimensional Kähler-Einstein manifolds. Different aspects of these solutions are analyzed; among them, the regularization of the on-shell Euclidean action by means of the addition of topological invariants. We also consider higher-curvature corrections to the gravity action that are cubic in the Riemann tensor and explicitly construct Eguchi-Hanson type solutions for such.

Current and future $B$-mode polarization data are the most powerful observables to constrain gravitational waves from the early Universe. We set conservative constraints on tensor modes when relaxing the inflationary consistency condition $n_{\mathrm{t}}=-r/8$ between the tensor tilt $n_{\mathrm{t}}$ and the tensor-to-scalar ratio $r$. By adding a power-law spectrum of tensor perturbations to $\mathrm{\Lambda }\mathrm{CDM}$ and parametrizing this tensor contribution by two independent primordial tensor-to-scalar ratios $(r_1,r_2)$ at $k_1=0.005{\mathrm{Mpc}}^{-1}$ and $k_2=0.02{\mathrm{Mpc}}^{-1}$, Planck and BICEP/Keck Array 2018 data (BK18) lead to constraints $r_{0.005}<0.030$ and $r_{0.02}<0.098$ at 95% confidence level. The corresponding upper bound $r_{0.01}<0.039$ is by a factor of 2 tighter than the one obtained with Planck 2018 and the older BK15 data. We then study the perspectives for future cosmic microwave background experiments that will measure both the reionization bump and recombination peak of the $B$-mode polarization angular power spectrum, such as LiteBIRD. We test the robustness of the results to the choice of the scales for $(r_1,r_2)$ in these future perspectives. Whereas distinguishing $n_{\mathrm{t}}=-r/8$ from exact scale invariance is impossible as expected, we show how radical, theoretically motivated departures from $n_{\mathrm{t}}=-r/8$, which are consistent with the current data, could be distinguished with LiteBIRD. Moreover, LiteBIRD will be able to shrink the allowed parameter space area in the $(r_{0.005},r_{0.02})$ plane to less than one hundredth of the currently allowed area by Planck 2018 and BK18.

We study background dynamics and the growth of matter perturbations in the extended quasidilaton setup of massive gravity. For the analysis of perturbations, we first choose a scalar field matter component and obtain the conditions under which all scalar perturbations are stable. We work in unitary gauge for the matter field, which allows us to directly map to known results in the limit of general relativity. By performing a parameter search, we find that the perturbations are unstable in general, while a particular choice of potential, where the scalar field effectively behaves like pressureless matter, allows for stable perturbations. We next consider the growth of matter perturbations in a cold dark matter-dominated Universe. Working in conformal Newtonian gauge, we obtain evolution equations for various observables including the growth factor and growth rate, and find scale-independent growth in the quasistatic and subhorizon approximations. We finally show how the Hubble parameter and matter perturbations evolve in massive gravity for a specific choice of parameter values, and how this evolution compares to the standard cosmological model consisting of a cosmological constant and cold dark matter.

Analysis of the charged multiplicity in proton-proton inelastic interactions at the LHC energies in the setting of the dual parton model is presented. Data from the CMS experiment and the data simulated at different energies in various pseudorapidity windows using the event generator pythia8 are analyzed and compared with the calculations from the model. Each inelastic scattering is assumed to follow the Poisson distribution. The Koba-Nielsen-Olesen (KNO) scaling of the multiplicity distributions is studied and compared with previously published experimental results at $\sqrt{s}=0.9$, 2.36, 7 TeV. Predictions from the model for the KNO distributions at $\sqrt{s}=13$, 13.6 TeV and for the future LHC energy of 27 TeV are computed and compared with the simulated data.

Lorentz- and $CPT$-violating effects initiating two-body electromagnetic flavor-changing decays of charged leptons are studied in the framework of Lorentz-violating effective field theory. An analysis of data from experiments at the Paul Scherrer Institute and at the Stanford Linear Accelerator measuring the branching ratios of these decays provides 576 constraints on independent flavor-changing effects in the charged-lepton sector, consistent with no Lorentz and $CPT$ violation at the level of parts in ${10}^{-13}–{10}^{-9}{\mathrm{GeV}}^{-1}$.