Improving the modeling of neutrino-nuclei interactions using data-driven methods is crucial for high-precision neutrino oscillation experiments. This paper investigates Peelle’s Pertinent Puzzle (PPP) in the context of neutrino measurements, a longstanding challenge to fitting theoretical models to experimental data. Inconsistencies in data-model comparisons hinder efforts to enhance the accuracy and reliability of model predictions. We analyze various sources contributing to these inconsistencies and propose strategies to address them, supported by practical case studies. We advocate for incorporating model fitting exercises as a standard practice in cross section publications to enhance the robustness of results. We use a common analysis framework to explore PPP-related challenges with MicroBooNE and T2K data in an unified manner. Our findings offer valuable insights for improving the accuracy and reliability of neutrino-nuclei interaction models, particularly by systematically tuning models using data.

We report dark photon results from HAYSTAC phase II using data from previously reported axion searches. Additionally, we present an analysis of an unpublished dataset covering a region between $19.46–19.52\mathrm{\mu eV}$. This region overlaps with a recently reported dark photon signal at $19.5\mathrm{\mu eV}$ with a kinetic coupling strength of $|{\chi }_{\mathrm{rand}}|\simeq 6.5\times {10}^{-15}$ resulting from a reanalysis of previously published data from the TASEH collaboration. Given HAYSTAC’s sensitivity, if such a signal were present, it would have appeared as a large $17.1\sigma$ excess above the noise. However, no such signal was observed. We thus exclude couplings $|{\chi }_{\mathrm{rand}}|\ge 4.90\times {10}^{-15}$ at the 90% confidence level over the newly reported region. In addition, using our previously reported axion data, we exclude couplings $|{\chi }_{\mathrm{rand}}|\ge 2.90\times {10}^{-15}$ between $16.96–19.46\mathrm{\mu eV}$ at the 90% confidence level.

We construct a family of closeness functions on the space of finite volume Lorentzian geometries using the abundance of discrete intervals in the underlying random causal sets. Although strictly weaker than a Lorentzian Gromov-Hausdorff distance function, it has the advantage of being numerically calculable for large causal sets. It thus provides a concrete and quantitative measure of continuumlike behavior in causal set theory and can be used to define a weak convergence condition for Lorentzian geometries.

An initially retrograde accretion flow is transformed into a prograde configuration before plunging into the black hole, as a result of the frame-dragging effect induced by the black hole’s rotation. The polarized image of a black hole shaped by such an accretion flow manifests three distinctive critical locations: the turning point of the flow’s primary image, the polarization handedness-flip location on the image plane, and the position of the primary image corresponding to the flow’s actual turning point in spacetime. Due to the influences of gravitational lensing and gravitational Faraday rotation, these three positions generally do not coincide. In this work, we examine a thin equatorial accretion disk composed of initially retrograde, geodesically moving flows, and conduct a systematic investigation into the interrelations and discrepancies among these critical locations. We elucidate the spatial hierarchy among the three, and for an on-axis observer, we derive approximate analytic expressions characterizing their positions.

We investigate gravitational waveforms from the inspiral phase of compact binary systems within the framework of quadratic gravity and map their deviations from general relativity into the parametrized post-Einstein (ppE) formalism to constrain the theory’s parameters. Quadratic gravity generically includes a massive spin-2 ghost, which leads to ill-defined energy and angular momentum fluxes. Following earlier proposals, we remove these unphysical features by imposing a constraint on the massive spin-2 mode, restricting it to propagate only the same polarizations of general relativity. Within the quadrupole approximation, we derive the radiative degrees of freedom, including massless and massive tensor modes, as well as a massive scalar field. Using the stationary phase approximation, we compute the Fourier-domain waveform of the massless tensor modes and extract the phase corrections. For small deviations from general relativity, we show that both the scalar and massive tensor modes can be consistently embedded into the ppE framework, extending previous results that considered only scalar fields. We derive updated constraints on the parameters of quadratic gravity, finding bounds improved by several orders of magnitude compared to existing limits. Finally, we present forecasts for the sensitivity of the Einstein Telescope to these deviations.

The LIGO Scientific, Virgo, and KAGRA collaboration has identified two binary neutron star merger candidates, GW170817 and GW190425, along with several binary black hole candidates. While GW170817 was confirmed as a binary neutron star merger through its electromagnetic counterparts, GW190425 lacked such observations, leaving its classification uncertain. We explore the possibility that GW190425 could have originated from black holes that merged after dark matter accretion caused their progenitor neutron stars to implode. Using this event, we place constraints on dark matter parameters, such as its mass and interaction cross section. We simulate GW190425-like events and analyze them using future gravitational wave detector networks, including upcoming upgrades to current detector networks and next-generation observatories. We show that a network with $\mathrm{A}+$ sensitivity can not classify a GW190425-like event with sufficient confidence. Detector networks with ${\mathrm{A}}^{♯}$ sensitivity can classify such events only if the neutron stars follow a relatively stiff equation of state, whose stronger tidal imprint differs measurably from a binary black hole waveform. Next-generation observatories like the Einstein Telescope and Cosmic Explorer recover the tidal signature even for soft, compact stars, enabling confident classification. Finally, we forecast the dark matter constraints that future gravitational wave networks could achieve for similar events.

We apply the renormalization group procedure for effective particles (RGPEP) to the front form Yukawa Hamiltonian, yielding a renormalized (effective) Hamiltonian, accurate up to second order in the coupling strength. Subsequently, we examine the spectrum and parton distribution functions produced by the renormalized Hamiltonian, and show that the addition of counterterms leads to finite results. Resource estimates for quantum simulation are calculated for a single “ladder operator block encoding” (LOBE), and show that the cost to block encode the renormalized Hamiltonian is comparable to block encoding the bare Hamiltonian.

Gravitational scattering of the electromagnetic field from a heavy scalar field provides a fundamental testbed for understanding the deflection of light by massive bodies. In many approaches based on effective field theory, the calculation of scattering amplitudes quickly becomes complicated due to the large number of Feynman integrals required, especially beyond leading order. In this work, we study this problem using effective field theory in the weak field approximation. We utilize the integration-by-parts reduction techniques to precisely examine the long-range contributions governed by terms in the amplitude that are nonanalytic in momentum transfer. Using geometric optics and the eikonal approximation, we derive expressions for the deflection angle and find the origin of differences relative to earlier works.

We study hydrodynamic theories with approximate symmetries in the recently developed effective action approach on the Schwinger-Keldysh contour. We employ the method of spurious symmetry transformation for small explicit symmetry-breaking parameters to systematically constrain symmetry-breaking effects in the nonequilibrium effective action for hydrodynamics. We apply our method to the hydrodynamic theory of chiral symmetry in quantum chromodynamics at finite temperature and density and its explicit breaking by quark masses. We show that the spurious symmetry and the Kubo-Martin-Schwinger relation dictate that the Ward-Takahashi identity for the axial symmetry, i.e., the partial conservation of axial vector current (PCAC) relation, contains a relaxational term proportional to the axial chemical potential, whose kinetic coefficient is at least of the second order in the quark mass. In the phase where the chiral symmetry is spontaneously broken, and the pseudo-Nambu-Goldstone pions appear as hydrodynamic variables, this relaxation effect is subleading compared to the conventional pion mass term in the PCAC relation, which is of the first order in the quark mass. On the other hand, in the chiral symmetry restored phase, we show that our relaxation term, which is of the second order in the quark mass, becomes the leading contribution to the axial charge relaxation. Therefore, the leading axial charge relaxation mechanism is parametrically different in the quark mass across a chiral phase transition.

S matrix principles and symmetries impose constraints on three-particle scattering amplitudes, which can be formulated as a class of integral equations for their partial wave projections. However, these amplitudes are typically expressed in an asymmetric basis, where one of the initial and final state particles is singled out, and all quantum numbers are defined relative to this spectator. In this work, we show how to construct symmetric partial wave amplitudes, which have been symmetrized over all possible spectator combinations, using their asymmetric counterparts and sets of recoupling coefficients. We derive these recoupling coefficients for arbitrary angular momentum and isospin for arbitrary systems of spinless particles with SU(2) flavor symmetry. We propose a simple intensity observable suitable for visualizing the structure of three-body dynamics in Dalitz distributions. Finally, we provide some numerical examples of Dalitz distributions relevant for future lattice QCD calculations of $3\pi$ systems and provide numerical evidence that the symmetrization procedure is consistent with expected symmetries of Dalitz plots.

We perform a numerical comparison between the fragmentation approach and the full $\mathcal{O}({\alpha }_s^5)$ calculation for the production of $J/\psi$ mesons in the partonic subprocess $q\overline{q}\to \psi ggg$. We make a similar comparison for the color-octet channel by considering the subprocess $gg\to {}^3{S}_1^{[8]}g$. We find that the nonfragmentation contributions in the color-singlet channel remain important up to $J/\psi$ transverse momenta as large as approximately 30 or 40 GeV, while the convergence of the factorized and full calculations in the color-octet channel is seen already at $p_{\psi T}\approx 10\mathrm{GeV}$.

A search for long-lived particles originating from the decay of $b$ hadrons produced in proton-proton collisions with a center-of-mass energy of 13 TeV at the LHC is presented. The analysis is performed on a dataset recorded in 2018, corresponding to an integrated luminosity of $41.6{\mathrm{fb}}^{-1}$. Interactions of the long-lived particles in the CMS endcap muon system would create hadronic or electromagnetic showers, producing clusters of detector hits. Selected events contain at least one such high-multiplicity cluster in the muon endcaps and require the presence of a displaced muon. The most stringent upper limits to date on the branching fraction $\mathcal{B}(B\to K\mathrm{\Phi })$, where the long-lived particle $\mathrm{\Phi }$ decays to a pair of hadrons, are obtained for $\mathrm{\Phi }$ masses of 0.3–3.0 GeV and $\mathrm{\Phi }$ mean proper decay lengths in the range of 1–500 cm.

Predictions from early Universe cosmology typically concern primordial perturbations generated during epochs where effects arising from the quantum nature of gravity may be important, with quantum vacuum fluctuations being stretched to cosmological scales during a phase of inflation. Quantizing the background is then done by assuming a single close-to-classical state over which perturbations grow, as well as a Born-Oppenheimer factorization throughout the relevant phase. We present a scenario in which although the latter factorization remains valid at all times, we allow the background state to be very nonclassical by defining quantum trajectories through an eikonal approximation. We find that these trajectories asymptotically reproduce an almost classical behavior for the background, but the predictions for the power spectrum of perturbations can significantly differ.

GW230529_181500 represented the first gravitational-wave detection with one of the component objects’ mass inferred to lie in the previously hypothesized mass gap between the heaviest neutron stars and the lightest observed black holes. Given the expected maximum mass values for neutron stars, this object was identified as a black hole, and, with the secondary component being a neutron star, the detection was classified as a neutron star-black hole merger. However, due to the low signal-to-noise ratio and the known waveform degeneracy between the spin and mass ratio in the employed gravitational-wave models, GW230529_181500 could also be interpreted as a merger of two heavy ($\gtrsim 2M_{\odot }$) neutron stars with high spins. We investigate the distinguishability of these scenarios by performing parameter estimation on simulated signals obtained from numerical-relativity waveforms for both neutron star-black hole and binary neutron star systems, with parameters consistent with GW230529_181500, and comparing them to the analysis of the real event data. We find that GW230529_181500 is more likely to have originated from a neutron star-black hole merger, though the possibility of a binary neutron star origin cannot be ruled out. Moreover, we use the simulation data to estimate the signatures of potential electromagnetic counterparts emitted by the systems. We find them to be too dim to be located by current wide-field surveys if only the dynamical ejecta is considered, and detectable by the Vera C. Rubin Observatory during the first two days after merger if one accounts for additional disk wind ejecta.

A key obstacle for theory-specific tests of general relativity is the lack of accurate black hole solutions in beyond-Einstein theories, especially for moderate to high spins. We address this by developing a general framework—based on spectral and pseudospectral methods—to obtain analytic, closed-form spacetimes representing stationary, axisymmetric black holes in effective-field-theory extensions of general relativity to leading order in the coupling constants. The approach models the spacetime (and extra fields) as a stationary, axisymmetric deformation of the Kerr metric in Boyer-Lindquist-like coordinates, expands metric deformations as a spectral series in radius and polar angle, and converts the resulting beyond-Einstein field equations into algebraic equations for the spectral coefficients. For any given spin, these equations are solved via standard linear-algebra methods; the coefficients are then fitted as functions of spin with nonlinear functions, yielding fully analytic metrics for rotating black holes in beyond-Einstein theories. We apply this to quadratic gravity theories—dynamical Chern-Simons, scalar-Gauss-Bonnet, and axidilaton gravity—obtaining solutions valid for any spin, including near-extremal cases with errors below machine precision for $a\le 0.9$ and $\lesssim {10}^{-8}$ for $a\le 0.999$. We show that existing slowly rotating solutions break down at $a\sim (0.2,0.6)$, depending on approximation order and chosen accuracy. We then use our metrics to compute observables, such as the surface gravity, horizon angular velocity, and the locations of the innermost circular orbit and the photon ring. The framework is general and applicable to other effective-field-theory extensions for black holes of any spin.

We compute the full cosmic trajectories of the early Universe across the QCD phase diagram as the plasma cools from $T\simeq 500\mathrm{MeV}$ to 30 MeV, assuming $\beta$-equilibrated matter. The trajectories are obtained by simultaneously solving baryon-number, electric-charge, and lepton-asymmetry conservation, closed by a state-of-the-art lattice-QCD equation of state: a fourth-order Taylor expansion in the chemical potentials that merges the latest ($2+1$)-flavor susceptibilities with charm-quark contributions, thus delivering a consistent $(2+1+1)$-flavor equation of state. Results are compared with an ideal quark-gluon plasma and with a hadron-resonance gas to highlight interaction effects. Two cases of primordial lepton asymmetries are analyzed: a symmetric configuration $({\ell }_e={\ell }_{\mu }={\ell }_{\tau }=\ell /3)$ and an asymmetric one $({\ell }_e=0,{\ell }_{\mu }=-{\ell }_{\tau })$. Increasing $|\ell |$ systematically drives the trajectories toward larger values of ${\mu }_B$ and more negative ${\mu }_Q$. In the asymmetric case, a nonmonotonic “bounce” develops when the $\tau$ chemical potential reaches $m_{\tau }$, generating a maximum in ${\mu }_B(T)$, the position of which depends on ${\ell }_{\tau }$. Assuming a modest ${\mu }_Q$ dependence of the lattice-QCD critical end point estimates (obtained at ${\mu }_Q=0$), the trajectories for all lepton asymmetries explored ($|\ell |\lesssim 0.1$) lie to their left, implying that in a standard cosmological scenario the QCD transition is almost certainly a smooth crossover. Nevertheless, we estimate the magnitude of baryon and lepton asymmetries needed to obtain a cosmic trajectory closer to the QCD critical point, providing inputs for future studies of the strong-interaction epoch.

Line intensity mapping (LIM) promises to probe previously inaccessible corners of the faint and high-redshift universe. However, confusion with bright foregrounds is a major challenge for current-era pathfinder LIM experiments. Cross-correlation with cosmic microwave background (CMB) lensing is a promising avenue to enable the first LIM detections at high redshifts, a pristine probe of fundamental physics but sparsely populated by faint galaxies, and to further probe the connection between matter and spectral line emission, expanding our understanding of galaxies and the IGM. Previous works have suggested that this direct correlation between LIM and CMB lensing is effectively impossible because smoothly varying modes in the intensity map are lost to bright foregrounds. In this work, we analytically revisit the direct correlation of foreground-filtered line intensity mapping with CMB lensing, highlighting lightcone evolution’s previously neglected yet unavoidable and crucial effects. Indeed, the growth of structure and evolution of line emission along the lightcone breaks statistical translational invariance and thus induces mode coupling, even in linear theory, which enables the recovery of the smoothly varying modes lost to bright foregrounds. We compute the effects of these lightcone evolution-induced mode couplings on the $\mathrm{LIM}\times \mathrm{CMB}$ lensing cross-spectrum detectability, predicting that future wider-sky versions of $\mathsf{COMAP}$ and $\mathsf{CCAT}$ will be able to precisely measure this cross-correlation. Although we focus on the direct correlation of LIM with CMB lensing in this paper, our arguments generalize to the direct correlation of LIM with any projected field.

The high-redshift ($z>10$) galaxies GHZ9 and UHZ1 observed by the James Webb Space Telescope are very massive and exhibit exceptionally high black-hole-to-star mass ratios with the central black hole masses $M\gtrsim {10}^7{M}_{\odot }$. In this paper, we explore the possibility that these systems are seeded by the supermassive primordial black holes (SMPBHs), which came into being in the very early Universe, with initial masses $\sim {10}^7{M}_{\odot }$. We present the self-similar accretion solutions for SMPBHs, and find that the mass growth of SMPBHs during the pregalactic era may be negligible. These SMPBHs, when the redshift $z\lesssim 20$, can accelerate seeding high-redshift galaxies and their baryonic content, and consequently explain the central supermassive black holes (SMBHs) of high-redshift massive galaxies through sub-Eddington accretion. According to our results, SMPBHs could lead to the existence of more massive SMBHs at higher redshifts compared to other SMBH seed scenarios. In particular, observations of SMBHs with masses $M\gtrsim {10}^7{\mathrm{M}}_{\odot }$ at $z>20$ could serve as potential probes of primordial black holes.

We present a two-stage upgrade to the pystampas pipeline that boosts the search for long–duration ($10–{10}^3\mathrm{s}$) transients in gravitational-wave detectors’ data. First, a denoising scheme combines complex 2-D wavelet shrinkage with adaptive pixel threshold to suppress noise while retaining signal power. Second, a KDTree nearest-neighbor algorithm clusters surviving pixels in $\mathcal{O}(\log (n))$ time, replacing the standard clustering approach. Tests with a week of LIGO O3b data show a large reduction in false alarm rate and an improvement of the search sensitivity by up to a factor 2. Moreover, the computational time has been significantly reduced. These gains extend the sensitivity of all-sky, all-time searches to weaker and shorter transients, paving the way for rapid and deeper analyses in forthcoming LIGO-Virgo-KAGRA observation campaigns.