We continue our series of papers where we study the quasinormal modes, and their excitation, of black holes in the simplest beyond general relativity model in which first-principle calculations are tractable: a nonrotating black hole in an effective-field-theory extension of general relativity with cubic-in-curvature terms. In this theory, the equivalence between the quasinormal mode spectra associated with metric perturbations of polar and axial parities (“isospectrality”) of the Schwarzschild black hole in general relativity no longer holds. How does this loss of isospectrality translate into the time-domain ringdown of gravitational waves? Given such a ringdown, can we identify the two “fundamental quasinormal modes” associated to the two metric-perturbation parities? We study these questions through a large suite of time-domain numerical simulations, by a prescription on how to relate the gauge-invariant master functions that describe metric perturbations of each parity with the gravitational polarizations. Under the assumptions made in our calculations, we find that it is in general difficult to identify either of the two fundamental modes from the time series, although finding evidence for a non-general-relativistic mode is possible sometimes. We discuss our results in light of our assumptions and speculate about what may occur when they are relaxed.

The Hubble tension, characterized by discrepant measurements of the Hubble constant from early and late Universe probes, remains one of the most significant challenges in cosmology. Building upon our previous analysis of individual parameter transitions in SH0ES data, we investigate the impact of simultaneous transitions in multiple Cepheid and SNIa calibration parameters at specific cosmic distances. We allow various combinations of transitions in Cepheid absolute magnitude ($M_H^W$), period-luminosity relation slope ($b_W$), metallicity coefficient ($Z_W$), and SNIa absolute magnitude ($M_B$). Our comprehensive analysis reveals a consistent preferred transition distance of approximately 23 Mpc across different parameter combinations. Our most akaike information criterion (AIC)-favored configuration is the dual-transition model ($M_B+Z_W$) at $D_c=23\mathrm{Mpc}$, yielding $\mathrm{\Delta }\mathrm{AIC}=-5.757$ and $\mathrm{\Delta }\mathrm{BIC}=+6.560$ relative to the baseline SH0ES model. While AIC moderately favors transition models across the $D_c$ scan, Bayesian information criterion (BIC) consistently prefers the baseline due to its stronger complexity penalty. Our primary, data-driven result is that the SH0ES data prefer transitions at $D_c\approx 23\mathrm{Mpc}$ by ${\chi }^2$ and AIC across model families; these models yield $H_0\approx 72–73\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$, maintaining tension with Planck, and $\mathrm{\Delta }\mathrm{BIC}$ remains positive. As a separate case study, the $M_B+Z_W$ model at $D_c=47\mathrm{Mpc}$ yields $H_0=64.4\pm 3.3\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$ (Planck compatible) but receives weaker statistical support and requires large parameter shifts. This demonstrates that calibration inhomogeneities of this form could, in principle, reconcile the tension, though we do not claim this configuration is preferred by the data.

When a gravitational wave encounters a massive object along the line of sight, repeated copies of the original signal may be produced due to gravitational lensing. In this paper, we develop a series of new machine-learning-based statistical methods to identify promising strong lensing candidates in gravitational wave catalogs. We employ state-of-the-art normalizing flow generative models to perform statistical calculations on the posterior distributions of gravitational wave events that would otherwise be computationally unfeasible. Our lensing identification strategy, developed on two simulated gravitational wave catalogs that test noise realization and event signal variations, selects event pairs with low parameter differences in the optimal detector basis that also have a high information content and favorable likelihood for coincident parameters. We then apply our method to the GWTC-3 catalog and find a single pair still consistent with the lensing hypothesis. This pair has been previously identified through more costly evidence ratio techniques, but rejected on astrophysical grounds, which further validates our technique.

This study presents a radiative three-loop model for neutrino mass generation, employing an asymmetric Yukawa coupling between two new scalar $SU(2{)}_L$ doublets and vectorlike lepton doublets. Dark matter candidates arise from one of the scalar doublets and contribute to neutrino mass generation through the mass splitting between its neutral components. The singly charged scalars are also essential for neutrino mass, with the charged states of the two doublets mixing with one another. A single generation of vectorlike leptons yields two nonzero neutrino masses as a consequence of the asymmetric Yukawa combinations entering the neutrino mass matrix. The model is tested against dark matter phenomenology, neutrino mass and mixing data, and the charged lepton flavor-violating process $\mu \to e\gamma$, showing compatibility with current bounds and leading to experimentally accessible predictions.

We show that multipartite entanglement can be used as an efficient way to identify the critical points of $1+1\mathrm{D}$ systems. We demonstrate this with the quantum Ising model, lattice $\lambda {\varphi }^4$ approximated with qutrits, and arrays of Rydberg atoms. To do so, we use multipartite compositions of entanglement quantities—$S_A$,$S_B$,$S_C$,$S_{AB}$,$S_{BC}$, and $S_{ABC}$—combined to form the strong subadditivity, weak monotonicity, and a convex combination of these with conformal properties. We will demonstrate how these bipartite entanglement quantities of a quadpartite system display behavior at phase boundaries, but the combination of these aforementioned quantities sharpens and localizes this behavior at the boundaries even better. We will show that we can extend a scheme for approximating the entanglement with the mutual information, and that this acts as a lower bound for the individual bipartite quantities. We show the mutual information will also follow the changes in the entanglement for the above combined quantities, despite no longer being a strict lower bound and the additional contributions of different signs. This mutual information approximation to the identifying quantities can have its lower probabilities removed in a process we call filtering, and despite the combination of terms with different signs, will respond well to the filtering and offer improvements to the lower bound.

Our understanding of high-lying states within the charmonium family remains incomplete, particularly in light of recent observations of charmonium states at energies around 4 GeV. In this study, we investigate the spectroscopic properties of several high-lying charmonia, focusing on the $2D$ and $1F$ states. A mass spectrum analysis is conducted, incorporating the unquenched effects. We then present a detailed study of the strong decay properties, including partial decay widths for two-body strong decays permitted by the Okubo-Zweig-Iizuka rule. Additionally, we explore the primary radiative decay channels associated with these states. Finally, we discuss the radiative transitions of the $2D$ and $1F$ states via $e^{+}{e}^{-}$ annihilation. Theoretical predictions provided here aim to guide future experimental searches for high-lying charmonium states at facilities such as BESIII, Belle II, LHCb, and the future Super $\tau$–Charm Facility.

The nucleon axial-vector form factor, $G_A$, is critical to determine the electroweak interactions of leptons with nucleons. Important examples of processes influenced by $G_A$ are elastic (anti)neutrino-nucleon scattering and muon capture by the proton. Sparse experimental data results in a large uncertainty on the momentum dependence of $G_A$ and has motivated the consideration of new experimental probes and first-principles lattice quantum chromodynamics (QCD) evaluations. The comparison of new and precise theoretical predictions for $G_A$ with future experimental data necessitates the application of radiative corrections to experimentally observable processes. We apply these corrections in the extraction of $G_A$ and the associated axial-vector radius from the recent MINERvA antineutrino-hydrogen data, compare the effects from radiative corrections to other uncertainties in neutrino scattering experiments, and discuss the comparison of lattice QCD evaluations to experimental measurements.

We perform a detailed analysis of semileptonic ${\mathrm{\Xi }}_b$ decays mediated by flavor-changing neutral currents ($b\to s$ and $b\to d$) with dilepton or dineutrino final states within the perturbative quantum chromodynamics (QCD) framework. All independent form factors including vector, axial-vector, tensor, and pseudotensor currents are calculated and are used to analyze the decay branching fractions and angular distributions. Our numerical results for the branching fractions of ${\mathrm{\Xi }}_b\to \mathrm{\Xi }{\ell }^{+}{\ell }^{-}$ decays suggest they are within measurable reach for the LHCb experiment in the near future. For the case of unpolarized ${\mathrm{\Xi }}_b$ baryons, we derive several angular observables, which can provide new and complementary constraints on Wilson coefficients in semileptonic flavor changing neutral current transitions compared to those from mesonic decays. Finally, we present a combined analysis of dilepton and dineutrino channels, comparing various observables in detail. Our results offer further insights into the long-standing anomalies observed in $B$ meson decays.

Black holes are believed to possess vanishing Love numbers, which implies that they do not deform in the presence of external tides. This fact has been verified in a number of scenarios that involve tides of bosonic fields of various natures (e.g., scalar, electromagnetic, and gravitational) and has triggered active research in trying to identify the underlying reason. Surprisingly, two counterexamples have been found recently. The first concerns charged-field tides on electrically charged black holes. In that case, however, the response cannot be disentangled from dissipative effects, and might thus be argued to not consist of a truly conservative deformation. The second concerns fermionic tides on neutral holes. While these yield a purely conservative response, they lack a classical interpretation, which is the physical regime where black hole deformability is understood. Here, we consider magnetic Reissner-Nordström black holes and show that electrically charged, scalar-field tides induce nonvanishing tidal Love numbers. We prove that this is a purely nondissipative effect, in contrast to the cases of rotating or electrically charged black holes, and hence consists of a genuine deformation. In addition, the magnetic charge resolves common ambiguities in defining Love numbers, so our result does not rely on any regularization scheme. This constitutes a clear realization of how new physics can influence black hole tidal deformability and offers new perspectives on the study of black hole Love numbers.

We study a five-leg scattering amplitude on the special Coulomb branch of planar $\mathcal{N}=4$ super Yang-Mills theory. We reach this point of the moduli space of scalar vacuum expectation values by considering six-dimensional $\mathcal{N}=(1,1)$ super Yang-Mills theory and reducing it down to four space-time dimensions with extradimensional momenta being nonvanishing. This branch is characterized by massive external W-bosons and massless internal gluons propagating in loops. We analyze the five W-boson amplitude in the kinematics when their masses are much smaller than all Mandelstam-like invariants. This is what we dub the near mass-shell limit. We perform calculations to two-loop order in ’t Hooft coupling, making use of recent advances in analytic calculations of required Feynman integrals. Our findings confirm exponentiation of infrared logarithms and enable us to conjecture a concise all-order expression for the amplitude in question. We further analyze its duality to the square root of a five-point correlation function of infinitely heavy half-BPS (Bogomol’nyi–Prasad–Sommerfield) operators, known as the decagon. By considering the near-null limit for inter-operators distances, we verify that the two objects coincide. This observation corroborates the novel Coulomb amplitudes/heavy correlator duality previously observed for four W-boson amplitudes and Sudakov form factors.

The response of a black hole (BH) to tidal forces encodes key information about the underlying gravitational theory and affects the waveform of gravitational waves emitted during binary inspiral processes. In this paper, we analyze the dynamical tidal response of static and spherically symmetric BHs in a low-frequency regime within general relativity (GR), based on a matching between the Mano-Suzuki-Takasugi (MST) methods for an analytical approach to BH perturbations and the worldline effective field theory (EFT) for an efficient and unified computation of the binary dynamics within the post-Newtonian regime. We show that the renormalized tidal response function is subject to inevitable ambiguities associated with the choice of renormalization scheme and with the initial condition of the renormalization flow equation. Once these ambiguities are fixed, we obtain scheme-dependent dynamical tidal Love numbers. We also discuss possible extensions of our formalism, including generic nonrotating compact objects (e.g., neutron stars) in GR and BHs in theories beyond GR.

Accurate modeling of gravitational waveforms from compact binary coalescences remains central to gravitational-wave (GW) astronomy. Post-Newtonian (PN) approximations capture the early inspiral dynamics analytically but break down near merger, while numerical relativity (NR) provides the accurate yet computationally expensive waveforms over limited parameter ranges. We develop a physics-informed neural network (PINN) framework that learns corrections mapping PN dynamics and waveforms to their NR counterparts. As a demonstration of the approach, we use the TaylorT4 PN model as the baseline, and train the network on a remarkably small dataset of only eight hybridized NR surrogate waveforms (NRHybSur3dq8) to learn higher-order corrections to the orbital dynamics and waveform modes for nonspinning noneccentric systems. Physically motivated loss terms enforce known limits and symmetries, such as vanishing corrections in the Newtonian limit and suppression of odd-$m$ modes in equal-mass systems, promoting consistent and reliable extrapolation beyond the training region. We simultaneously incorporate corrections that account for the different meaning of mass parameters in PN and NR descriptions. The learned corrections significantly reduce the phase and amplitude error through the inspiral up to about $200M$ before the merger. This approach provides a differentiable and computationally efficient bridge between PN and NR, offering a path toward waveform models that generalize more robustly beyond existing NR datasets.

Dark sector interactions can be explored via the so-called type 3 model where dark matter and dark energy exchange momentum only, so as to minimize deviations from the $\mathrm{\Lambda }$ cold dark matter background expansion history. Using N-body simulations, we analyze the imprint of type 3 model parameters, the momentum exchange coupling constant $\beta$ and the slope of scalar field potential $\lambda$, on large-scale structure observables, particularly the matter pairwise velocity statistics. We find that the effects of $\beta$ ($<0$) and $\lambda$ on the mean matter peculiar pairwise velocity and velocity dispersion are degenerate. Our results highlight the potential of velocity statistics as a probe of dark sector interactions and underscore the importance of disentangling $\beta$ and $\lambda$ in cosmological analyses.

We investigate the properties of gravitational waves generated by heating-induced phase transitions in warm inflation. In this scenario, the heating phase of inflation followed by subsequent cosmological cooling can trigger two associated first-order phase transitions and generate characteristic gravitational waves. The correlated gravitational wave spectral features—amplitude, peak frequencies, and oscillatory behavior—originate from a unified model governing both phase transitions. These signatures allow discrimination between warm and cold inflation models, and give constraint on the key parameters including the dissipative coupling strength and the inflationary energy scale, collectively illuminating early-Universe dissipative dynamics. Future gravitational wave observatories such as BBO, Ultimate-DECIGO, $\mu \mathrm{Ares}$, resonant cavities, and Pulsar Timing Array experiments, will play a important role in testing these theoretical predictions.

We present relativistic $N$-body simulations of a ${\mathrm{\Lambda }}_{\mathrm{s}}\mathrm{CDM}$—sign-switching cosmological constant (CC)—scenario under general relativity and compare its nonlinear matter power spectrum to $\mathrm{\Lambda }\mathrm{CDM}$ at $z=15$, 2, 1, 0, using best-fit parameters from Planck-only and a combined “full” dataset. During the AdS-like CC (${\mathrm{\Lambda }}_{\mathrm{s}}<0$) phase, prior to the transition redshift $z_{†}$, reduced Hubble friction dynamically enhances the growth of perturbations; after the switch, with dS-like CC (${\mathrm{\Lambda }}_{\mathrm{s}}>0$), the larger late-time expansion rate partly suppresses, but does not erase, the earlier amplification. Consequently, the ratio $P_{{\mathrm{\Lambda }}_{\mathrm{s}}\mathrm{CDM}}/P_{\mathrm{\Lambda }\mathrm{CDM}}$ exhibits a pronounced, redshift-dependent shape feature: a crest peaking at about 20%–25% around $k\simeq 1–3h{\mathrm{Mpc}}^{-1}$ near the transition, which then migrates to larger physical scales and persists to $z=0$ as a robust uplift of around 15%–20% at $k\simeq 0.6–1.0h{\mathrm{Mpc}}^{-1}$. These wave numbers correspond to group or poor-cluster environments and lie within the sensitivity range of weak lensing, galaxy-galaxy lensing, cluster counts, and thermal Sunyaev-Zel’dovich power, providing a concrete, falsifiable target that cannot be mimicked by a scale-independent change in ${\sigma }_8$ or $S_8$. The timing (earlier for Planck-only, later for the full dataset) and the amplitude of the crest align with the “cosmic noon” epoch ($z\simeq 1–2$), offering a gravitational prior for the observed peak in the cosmic star-formation rate.

The “hyperon puzzle” remains a fundamental challenge in nuclear astrophysics. We investigate hyperon emergence in neutron star matter using the $SU(3)$ parity doublet model with chiral representation $(3,\overline{3})+(\overline{3},3)$. This framework naturally incorporates chiral symmetry restoration and provides a systematic description of baryon masses in dense matter through the interplay between the chiral condensate and the chiral invariant mass $m_0$. We find that the hyperon onset density exhibits strong sensitivity to $m_0$: for $m_0=500\mathrm{MeV}$, hyperons first appear at $1.9n_0$, while for $m_0\gtrsim 750\mathrm{MeV}$, hyperons emerge only above $5n_0$. This delayed onset arises from the weakened density dependence of baryon masses at larger $m_0$ values. When the hyperon onset density exceeds the expected quark-hadron transition range ($2–5n_0$), matter undergoes deconfinement before hyperons populate, avoiding the equation of state softening while maintaining consistency with massive neutron star observations. Our results demonstrate that chiral dynamics provides a natural resolution to the hyperon puzzle without requiring ad hoc repulsive hyperon interactions.

The spectroscopy of the $3^{++}$ light-meson candidates, in particular the $a_3$ and $f_3$ families, remains an open issue. We compute the mass spectra in the modified Godfrey-Isgur model and evaluate the Okubo-Zweig-Iizuka-allowed two-body strong decays within the quark-pair-creation model. Our analysis favors the interpretation that $a_3(1875)$ and $a_3(2030)$ correspond to the same resonance, identified as the $a_3$ ground state, while $f_3(2050)$ is the ground state of the $f_3$ family; furthermore, $a_3(2275)$ and $f_3(2300)$ are assigned as their first radial excited states. For other higher-excitation states, we provide predictions for the decay behaviors and include the mass-induced model uncertainty.

Recent measurements at the Large Hadron Collider have observed entanglement in the spins of $t\overline{t}$ pairs. The effects of radiation, which are expected to lead to quantum decoherence and a reduction of entanglement, are generally neglected in such measurements. In this work we calculate the effects of decoherence from various different types of radiation for a maximally entangled pair of fermions—a bipartite system of qubits in a Bell state. We identify the Kraus operators describing the evolution of the open quantum system with the integrated Altarelli-Parisi splitting functions.

In all previous calculations of the nonlocal subleading contribution to the inclusive penguin decay $\overline{B}\to X_s\gamma$ due to the interference of the electroweak operators ${\mathcal{O}}_1^c-{\mathcal{O}}_{7\gamma }$ the local Voloshin term was subtracted. In view of the ongoing analysis at order ${\alpha }_s$, we present a calculation of the complete nonlocal contribution which takes into account the high correlation between the uncertainties of the local Voloshin and the nonlocal term of the previous analyses. The new calculation has a high impact on the range of the nonlocal contribution.