The weak cosmic censorship conjecture (WCCC) of black holes is a fundamental hypothesis in general relativity. The proof of this hypothesis has become a frontier issue in the study of gravity. Recently, Sorce and Wald proposed a new version of the gedanken experiment and examined that the WCCC of Kerr-Newman (KN) black holes is valid under the second-order approximation of the matter fields perturbation. But it is not enough to study the WCCC under the second-order approximation because there is an additional condition that makes the validity of the hypothesis impossible to judge in this case. Therefore, the higher-order approximation of the perturbation process should be further considered to examine the conjecture strictly. Based on the new version of the gedanken experiment, from the two assumptions that the spacetime geometry satisfies the stability condition and that the matter fields should obey the null energy condition, we deduce the $n$th-order perturbation inequality and demonstrate that the event horizon of KN black holes always exists under the $n$th-order approximation of the matter fields perturbation. It indicates that the hypothesis is always satisfied under the arbitrary high-order approximation and also shows that the WCCC of KN black holes has been examined rigorously at the perturbation level.

The new measurement of $W$-boson mass by the CDF collaboration revealed a remarkable $7\sigma$ disagreement with the Standard Model (SM) prediction. If confirmed by other experiments, then the disagreement strongly indicates the existence of new physics beyond the SM. In this work, seven vectorlike quark (VLQ) extensions of the SM are investigated to interpret the anomaly, and it is found that three can explain the anomaly in broad parameter space. The explanations are consistent with the constraints from oblique parameters, the LHC search for VLQs, the measurements of the properties for the top quark, bottom quark, and Higgs boson, and the perturbativity criterion. The typical size of the involved Yukawa coupling is around 1, which is comparable to the top quark Yukawa coupling in the SM. The other extensions, however, either predict a negative correction to the mass in reasonable parameter space or explain the anomaly by unnatural theoretical input parameters.

In the real-time formalism of the finite-temperature field theory, we compute the one-loop gluon self-energy in a semiquark-gluon plasma (QGP) where a background field $\mathcal{Q}$ has been introduced for the vector potential, leading to a nontrivial expectation value for the Polyakov loop in the deconfined phase. Explicit results of the gluon self-energies up to the next-to-leading order in the hard-thermal-loop approximation are obtained. We find that for the retarded/advanced gluon self-energy, the corresponding contributions at next-to-leading order are formally analogous to the well-known result at $\mathcal{Q}=0$ where the background field modification on the Debye mass is entirely encoded in the second Bernoulli polynomials. The same feature is shared by the leading order contributions in the symmetric gluon self-energy where the background field modification becomes more complicated, including both trigonometric functions and the Bernoulli polynomials. These contributions are nonvanishing and reproduce the correct limit as $\mathcal{Q}\to 0$. In addition, the leading order contributions to the retarded/advanced gluon self-energy and the next-to-leading order contributions to the symmetric gluon self-energy are completely new as they only survive at $\mathcal{Q}\ne 0$. Given the above results, we explicitly verify that the Kubo-Martin-Schwinger condition can be satisfied in a semi-QGP with a nonzero background field.

We investigate the quark spin content of the SU(3) baryon octet, decuplet, antitriplet, and sextet in a pion mean-field approach or the chiral quark-soliton model, considering the $1/N_c$ rotational corrections and SU(3) symmetry breaking effects. We compare the present results with those from various theoretical works and lattice QCD.

The finite size of a neutrino wave packet at creation can affect its oscillation probability. Here, we consider the electron antineutrino wave packet and decoherence in the context of the nuclear reactor-based experiment JUNO. Given JUNO’s high expected statistics [$\sim 100\mathrm{k}$ IBD events (${\overline{\nu }}_{e}p\to e^{+}n$)], long baseline ($\sim 53\mathrm{km}$), and excellent energy resolution [$\sim 0.03/\sqrt{E_{\mathrm{vis}}(\mathrm{MeV})}$], its sensitivity to the size of the wave packet is expected to be quite strong. Unfortunately, this sensitivity may weaken the experiment’s ability to measure the orientation of the neutrino mass hierarchy for currently allowed values of the wave-packet size. Here, we report both the JUNO experiment’s ability to determine the hierarchy orientation in the presence of a finite wave packet and its simultaneous sensitivity to size of the wave packet and the hierarchy. We find that wave-packet effects are relevant for the hierarchy determination up to nearly two orders of magnitude above the current experimental lower limit on the size, noting that there is no theoretical consensus on the expectation of this value. We also consider the effect in the context of other aspects of JUNO’s nominal three-neutrino oscillation measurement physics program and the prospect of future enhancements to sensitivity, including from precise measurements of $\mathrm{\Delta }{m}_{3l}^2$ and a near detector.

We discuss the prospects of probing the $L_{\mu }-L_{\tau }$ gauge boson at the MUonE experiment. The $L_{\mu }-L_{\tau }$ gauge boson $Z^{\prime }$ with a mass of $\lesssim 200\mathrm{MeV}$, which can explain the discrepancy between the measured value of the muon $g-2$ and the value calculated in the Standard Model, can be produced at the MUonE experiment through the process $\mu e\to \mu e{Z}^{\prime }$. The $Z^{\prime }$ in the final state decays into a pair of neutrinos, and therefore we cannot observe the decay of $Z^{\prime }$ directly. It is, however, still possible to probe this signature by searching for events with a large scattering angle of muon and a less energetic final-state electron. The background events coming from the elastic scattering $\mu e\to \mu e$ as well as radiative process $\mu e\to \mu e\gamma$ can be removed by the kinematical cuts on the muon scattering angle and the electron energy, in addition to a photon veto. The background events from the electroweak process $\mu e\to \mu e\nu \overline{\nu }$ are negligible. With our selection criteria, the number of signal events $\mu e\to \mu e{Z}^{\prime }$ is found to be as large as $\sim {10}^3$, assuming an integrated luminosity of $15{\mathrm{fb}}^{-1}$, in the parameter region motivated by the muon $g-2$ discrepancy. It is, therefore, quite feasible to probe the $L_{\mu }-L_{\tau }$ gauge boson at the MUonE experiment—without introducing additional devices—and we strongly recommend recording the events relevant to this $Z^{\prime }$ production process.

Building upon several recent advances in the developmentof effective-one-body (EOB) models for spin-aligned eccentric binaries with individual masses $(m_1,m_2)$, we introduce a new EOB waveform model that aims at describing inspiraling binaries in the large mass-ratio regime, $m_1\gg m_2$. The model exploits the current state-of-the-art TEOBResumS-DALI model for eccentric binaries, but the standard EOB potentials $(A,\overline{D},Q)$, informed by numerical relativity (NR) simulations, are replaced with the corresponding functions that are linear in the symmetric mass ratio $\nu \equiv m_1{m}_2/(m_1+m_2{)}^2$ taken at 8.5PN (Post-Newtonian) accuracy. To improve their strong-field behavior, these functions are (i) suitably factorized and resummed using Padé approximants and (ii) additionally effectively informed to state-of-the-art numerical results obtained by gravitational self-force theory (GSF). For simplicity, the spin sector of the model is taken to be the one of TEOBResumS-DALI, though removing the NR-informed spin-orbit effective corrections. We propose the current GSF-informed EOB framework as a conceptually complete analytical tool to generate waveforms for eccentric extreme (and intermediate) mass ratio inspirals for future gravitational wave detectors.

A possible way to capture the effects of quantum gravity in spacetime at a mesoscopic scale, for relatively low energies, is through an energy-dependent metric, such that particles with different energies probe different spacetimes. In this context, a clear connection between a geometrical approach and modifications of the special relativistic kinematics has been shown in the last few years. In this work, we focus on the geometrical interpretation of the relativistic deformed kinematics present in the framework of doubly special relativity, where a relativity principle is present. In this setting, we study the effects of a momentum dependence of the metric for a uniformly accelerated observer. We show how the local Rindler wedge description gets affected by the proposed observer-dependent metric, while the local Rindler causal structure is not, leading to a standard local causal horizon thermodynamic description. For the proposed modified metric, we can reproduce the derivation of Einstein’s equations as the equations of state for the thermal Rindler wedge. The conservation of the Einstein tensor leads to the same privileged momentum basis obtained in other works of some of the present authors, so supporting its relevance.

We perform $N$-body simulations for $f(T)$ gravity using the ME-Gadget code, in order to investigate the structure formation process in detail for the first time. Focusing on the power-law model and considering the model parameter to be consistent within $1\sigma$ with all other cosmological data sets (such as type 1a supernovae, baryon acoustic oscillations, the cosmic microwave background, and cosmic chronometers), we show that there are clear observational differences between $\mathrm{\Lambda }\mathrm{CDM}$ cosmology and $f(T)$ gravity due to the modifications brought about by the latter in the evolution of the Hubble function and the effective Newton’s constant. We extract the matter density distribution, matter power spectrum, counts-in-cells, halo mass function, and excess surface density (ESD) around low-density positions (LDPs) at the present time. Concerning the matter power spectrum, we find a difference from that in the $\mathrm{\Lambda }\mathrm{CDM}$ scenario, about $2/3$ of which is attributed to the different expansion and about $1/3$ to the effective gravitational constant. Additionally, we find a difference in the cells, which is significantly larger than the Poisson error, which may be distinguishable with weak-lensing reconstructed mass maps. Moreover, we show that there are different massive halos with masses $M>{10}^{14}{M}_{\odot }/h$, which may be distinguishable from statistical measurements of cluster number counting, and we find that the ESD around LDPs is mildly different. In conclusion, by highlighting possible smoking guns, we show that large-scale structure can indeed lead us to distinguish general relativity and $\mathrm{\Lambda }\mathrm{CDM}$ cosmology from $f(T)$ gravity.

The search for primordial $B$-mode polarization of the cosmic microwave background (CMB) is limited by the sample variance of $B$-modes produced at later times by gravitational lensing. Constraints can be improved by “delensing”: using some proxy of the matter distribution to partially remove the lensing-induced $B$-modes. Current and soon-upcoming experiments will infer a matter map—at least in part—from the temperature anisotropies of the CMB. These reconstructions are contaminated by extragalactic foregrounds: radio-emitting galaxies, the cosmic infrared background, or the Sunyaev-Zel’dovich effects. Using the Websky simulations, we show that the foregrounds add spurious power to the angular autospectrum of delensed $B$-modes via non-Gaussian higher-point functions, biasing constraints on the tensor-to-scalar ratio, $r$. We consider an idealized experiment similar to the Simons Observatory, with no Galactic or atmospheric foregrounds. After removing point sources detectable at 143 GHz and reconstructing lensing from CMB temperature modes $l<3500$ using a Hu-Okamoto quadratic estimator (QE), we infer a value of $r$ that is $1.5\sigma$ higher than the true $r=0$. Reconstructing instead from a minimum-variance internal linear combination map only exacerbates the problem, bringing the bias above $3\sigma$. When the $TT$ estimator is co-added with other QEs or with external matter tracers, new couplings ensue which partially cancel the diluted bias from $TT$. We provide a simple and effective prescription to model these effects. In addition, we demonstrate that the point-source-hardened or shear-only QEs can not only mitigate the biases to acceptable levels but also lead to lower power than the Hu-Okamoto QE after delensing. Thus, temperature-based reconstructions remain powerful tools in the quest to measure $r$.

The kinetic Sunyaev-Zel’dovich effect is a secondary CMB temperature anisotropy that provides a powerful probe of the radial-velocity field of matter distributed across the Universe. This velocity field is reconstructed by combining high-resolution CMB measurements with galaxy survey data, and it provides an unbiased tracer of matter perturbations in the linear regime. In this paper, we show how this measurement can be used to probe primordial non-Gaussianity of the local type, particularly focusing on the trispectrum amplitude ${\tau }_{\mathrm{NL}}$, as may arise in a simple two-field inflation model that we provide by way of illustration. Cross-correlating the velocity-field-derived matter distribution with the biased large-scale galaxy density field allows one to measure the scale-dependent bias factor with sample variance cancellation. We forecast that a configuration corresponding to CMB-S4 and VRO results in a sensitivity of ${\sigma }_{f_{\mathrm{NL}}}\approx 0.59$ and ${\sigma }_{{\tau }_{\mathrm{NL}}}\approx 1.5$. These forecasts predict improvement factors of 10 and 195 for ${\sigma }_{f_{\mathrm{NL}}}$ and ${\sigma }_{{\tau }_{\mathrm{NL}}}$, respectively, over the sensitivity using VRO data alone, without internal sample variance cancellation. Similarly, for a configuration corresponding to DESI and SO, we forecast a sensitivity of ${\sigma }_{f_{\mathrm{NL}}}\approx 3.1$ and ${\sigma }_{{\tau }_{\mathrm{NL}}}\approx 69$, with improvement factors of 2 and 5, respectively, over the use of the DESI data set in isolation. We find that a high galaxy number density and large survey volume considerably improve our ability to probe the amplitude of the primordial trispectrum for the multifield model considered.

We investigate the far-from-equilibrium behavior of the Boltzmann equation for a gas of massless scalar field particles with quartic (tree level) self-interactions ($\lambda {\varphi }^4$) in Friedmann-Lemaitre-Robertson-Walker spacetime. Using a new covariant generating function for the moments of the Boltzmann distribution function, we analytically determine a subset of the spectrum and the corresponding eigenfunctions of the linearized Boltzmann collision operator. We show how the covariant generating function can be also used to find the exact equations for the moments in the full nonlinear regime. Different than the case of a ultrarelativistic gas of hard spheres (where the total cross section is constant), for $\lambda {\varphi }^4$ the fact that the cross section decreases with energy implies that moments of arbitrarily high order directly couple to low order moments. Numerical solutions for the scalar field case are presented and compared to those found for a gas of hard spheres.

We obtain an improved determination of the normalization of the leading infrared renormalon of the Bjorken sum rule: $Z_B(n_f=3)=-0.407\pm 0.119$. Estimates of higher order terms of the perturbative series are given. We compute the Bjorken sum rule with hyperasymptotic precision by including the leading terminant, associated with the first infrared renormalon. We fit the experimental data to the operator product expansion theoretical prediction with ${\widehat{f}}_3^{\mathrm{PV}}$ as the free parameter. We obtain a good agreement with the experiment with ${\widehat{f}}_3^{\mathrm{PV}}\times {10}^3=32_{-196}^{+187}{\mathrm{GeV}}^2$ for $Q^2\ge 1{\mathrm{GeV}}^2$.

With the new measurements of $X(3872)\to J/\psi {\pi }^{+}{\pi }^{-}$ from LHCb Collaboration, in addition to the dominant contribution from the ${\rho }^0$ meson, we perform a theoretical study on the contribution of $\omega$ meson in the $X(3872)\to J/\psi {\pi }^{+}{\pi }^{-}$ and $X(3872)\to J/\psi {\pi }^{+}{\pi }^{-}{\pi }^0$ processes. For the $X(3872)\to J/\psi {\pi }^{+}{\pi }^{-}$ decay, in addition to the main contribution from ${\rho }^0$ meson, we consider also the $X(3872)J/\psi \omega$ coupling with $\omega$ meson decaying directly into ${\pi }^{+}{\pi }^{-}$. It is found that the recent experimental measurements on the ${\pi }^{+}{\pi }^{-}$ invariant mass distributions can be well reproduced, and the ratio of the couplings between $X(3872)\to J/\psi {\rho }^0$ and $X(3872)\to J/\psi \omega$ is also evaluated. Within the parameters extracted from the ${\pi }^{+}{\pi }^{-}$ invariant mass distributions of the $X(3872)\to J/\psi {\pi }^{+}{\pi }^{-}$ process, the branching fractions of the $X(3872)\to J/\psi \omega$ channel relative to that of the $X(3872)\to J/\psi {\pi }^{+}{\pi }^{-}{\pi }^0$ channel and the ${\pi }^{+}{\pi }^{-}{\pi }^0$ invariant mass distributions of the $X(3872)\to J/\psi {\pi }^{+}{\pi }^{-}{\pi }^0$ decay are calculated, which gives a hint for the further high-statistic experiment.

The lepton number and flavor violations are important possible ingredients of the lepton physics. The neutrinoless double beta decay and the transition of the muonium into antimuonuim are related to those violations. The former can give us an essential part of fundamental physics, and there are plenty of experimental attempts to observe the process. The latter has also been one of the attractive phenomena, and the experimental bound will be updated in planned experiments at new high-intensity muon beamlines. In models with a doubly charged scalar, not only can those two processes be induced, but also the active neutrino masses can be induced radiatively. The flavor violating decays of the charged leptons constrain the flavor parameters of the models. We study how the muonium-to-antimuonium transition rate can be as large as the current experimental bound, and we insist that the updated bound of the transition rate will be useful to distinguish the models to generate the neutrinoless double beta decay via the doubly charged scalar. We also study a possible extension of the model to the left-right model which can induce the neutrinoless double beta decay.

Since there is no fundamental charged scalar boson in the Standard Model (SM) of particle physics then the discovery of each charged scalar boson would clearly represent an instant evidence of physics beyond the SM. In this regard, searching for charged Higgs bosons is unique and have been the center of attention of colliders such as the CERN LHC. In the present work, we study a proposed channel to search for heavy charged Higgses at the current and future colliders. In this channel we study the scaled-energy distribution of bottom-flavored mesons ($B$) inclusively produced in heavy charged Higgs decay, i.e., $H^{+}\to t\overline{b}\to B+X$. This study is performed within the framework of two Higgs doublet model using the general-mass variable-flavor-number scheme where the $b$-quark mass is preserved from the beginning. Our results will be compared with the ones calculated in the zero-mass variable-flavor-number scheme where the zero mass approximation is adopted for the bottom quark. We find that most reliable predictions can be achieved through the massive scheme.

Octet baryon axial, induced pseudoscalar, and pseudoscalar form factors are computed using a symmetry-preserving treatment of a vector $\times$ vector contact interaction (SCI), thereby unifying them with an array of other baryon properties and analogous treatments of semileptonic decays of pseudoscalar mesons. The baryons are treated as quark-plus-interacting-diquark bound states, whose structure is obtained by solving a Poincaré-covariant Faddeev equation. The approach is marked by algebraic simplicity and involves no free parameters, and, since it is symmetry preserving, all consequences of partial conservation of the axial current are manifest. It is found that SCI results are consistent with only small violations of SU(3)-flavor symmetry, an outcome which may be understood as a dynamical consequence of emergent hadron mass. The spin-flavor structure of the Poincaré-covariant baryon wave functions is expressed in the presence of both flavor-antitriplet–scalar diquarks and flavor-sextet–axial-vector diquarks and plays a key role in determining all form factors. Considering neutral axial currents, SCI predictions for the flavor separation of octet baryon axial charges and, therefrom, values for the associated SU(3) singlet, triplet, and octet axial charges are obtained. The results indicate that, at the hadron scale ${\zeta }_{\mathcal{H}}$, valence degrees of freedom carry roughly 50% of an octet baryon’s total spin. Since there are no other degrees of freedom at ${\zeta }_{\mathcal{H}}$, the remainder may be associated with $\mathrm{quark}+\mathrm{diquark}$ orbital angular momentum.

We numerically estimate the divergence of several two-vertex diagrams that contribute to the radiative corrections for the Lorentzian Engle-Pereira-Rovelli-Livine spin foam propagator. We compute the amplitudes as functions of a homogeneous cutoff over the bulk quantum numbers, fixed boundary data, and different Immirzi parameters, and find that for a class of two-vertex diagrams, those with fewer than six internal faces are convergent. The calculations are done with the numerical framework sl2cfoam-next.

The Moore-Read state is one of the most well-known non-Abelian fractional quantum Hall states. It supports non-Abelian Ising anyons in the bulk and a chiral bosonic and chiral Majorana modes on the boundary. It has been recently conjectured that these modes are superpartners of each other and described by a supersymmetric conformal field theory [K. K. W. Ma et al., Phys. Rev. Lett. 126, 206801 (2021).]. We propose a nonrelativistic supergeometric theory that is compatible with this picture and gives rise to an effective spin-$3/2$ field in the bulk. After breaking supersymmetry through a Goldstino, the spin-$3/2$ field becomes massive and can be seen as the neutral collective mode that characterizes the Moore-Read state. By integrating out this fermion field, we obtain a purely bosonic topological action that properly encodes the Hall conductivity, Hall viscosity and gravitational anomaly. Our work paves the way to the exploration of the fractional quantum Hall effect through nonrelativistic supergeometry.

We investigate neutrino flavor oscillations in vacuum within a general conformal coupling model. We first examine the flavor oscillations within the plane-wave description of neutrinos, and then we extend our analysis to the wave-packet-based formalism. In both cases, we derive the general formulas for the flavor transition probability in arbitrary static and spherically symmetric spacetimes. We thoroughly discuss and assess in both cases the different possible ways—dictated by the presence of the conformal coupling—of computing the flavor transition probability. We show that the conformal invariance of the Dirac equation implies that the effect of conformal coupling on neutrino flavor oscillations modifies the oscillation length but preserves the coherence length and unitarity. A detailed application to two-flavor neutrinos is then made, and a numerical analysis is conducted within the well-known chameleon conformal coupling model.