Gravitational-wave observations reveal that the rate of merging black holes drops by $\sim 2$ orders of magnitude from component masses $\sim 10M_{\odot }$ to $\sim 15M_{\odot }$. The increased compactness of the black hole progenitor cores may contribute to the $\sim 10M_{\odot }$ overdensity, but cannot fully explain the rate difference. In this paper, we consider the possibility that the overdensity is reinforced by supernova processes that result in efficient black hole formation from direct collapse in a narrow range around $10M_{\odot }$. We extend previous studies by considering a distinct subpopulation of failed-supernovae black holes, possibly separated by a gap in the primary mass distribution from the rest of the population. Using 153 observations from the latest GWTC-4.0 catalog, we confirm a strong peak in the primary mass distribution at $10M_{\odot }$, with a peak rate density of ${7.36}_{-3.11}^{+6.35}$ $M_{\odot }^{-1}{\mathrm{yr}}^{-1}{\mathrm{Gpc}}^{-3}$. The rate drops sharply and becomes consistent with zero at the 90% level for primary mass $m_1\in (12.0,16.1)M_{\odot }$, then rises again to confidently nonzero values above $\sim 16M_{\odot }$ before falling at higher masses. Our results reveal structure in the mass distribution in the $10-20M_{\odot }$ range, with rate changes of multiple orders of magnitude across a few solar masses, consistent with a distinct population of failed-supernova black holes. These conclusions persist in the latest GWTC-5.0 catalog.

String theory naturally leads to the expectation that dark energy is not stable, and may be evolving as captured by the Swampland de Sitter conjectures. Moreover, motivated by the distance conjecture, a unification of dark sector has been proposed, where the smallness of dark energy leads to one extra dimension of micron size with dark matter being the Kaluza-Klein graviton excitations in this extra dimension. We consider the natural possibility that the radius of the dark dimension varies as the energy decreases, leading to the variation of the dark matter mass. This correlates the variation of the dark energy with the variation of the dark matter mass as they depend on the variations of a scalar field $\varphi$ controlling the radius of the extra dimension. A simple realization of this idea for small range of $\varphi$ is adequately captured by choosing a potential which is locally of the form $V=V_0\exp (-c\varphi )$ and dark matter mass $m_{\mathrm{DM}}=m_0\exp (-c^{\prime }\varphi )$ as was proposed in [1]. We find excellent agreement with recent experimental data from DESI DR2 combined with SN measurements (from DES, Union3 or Pantheon+) and reproduces the same significance as Chevallier–Polarski–Linder parametrization with the added benefit of providing a natural explanation for the apparent phantom behavior ($w<-1$) reported by DESI and DES based on a physical model. DESI and SN datasets independently favor nonzero values of $c^{\prime }$ and $c$, respectively, both lying within the expected $\mathcal{O}(1)$ range suggested by the Swampland criteria. Moreover, our best fit value $c^{\prime }\simeq 0.05\pm 0.01$ is remarkably consistent with the experimental upper bound of $c^{\prime }\lesssim 0.2$ demanded by the lack of detection of fifth force in the dark sector.

We present the first high-significance spectroscopic stacked kinetic Sunyaev-Zel’dovich (kSZ) measurements of circumgalactic gas profiles for both bright galaxy survey (BGS) and emission line galaxy (ELG) tracers, combining DESI Data Release 2 with ACT Data Release 6. Using reconstructed line-of-sight velocities from the DESI galaxies and high-resolution ACT temperature maps, we detect the kSZ signal at high significance, reaching signal-to-noise ratios of up to $\sim 9$ for BGS and $\sim 7.5$ for ELGs in optimal stellar-mass selections. Together with the Luminous red galaxies (LRGs) measurements presented in Paper I, these constitute the most significant kSZ detections from any spectroscopic survey to date. We perform the analysis in both real and harmonic space, obtaining consistent results. By splitting both tracers into stellar-mass bins, we study the scaling of the kSZ amplitude with galaxy properties. Combining the kSZ measurements with ACT Data Release 6 (DR6) cosmic microwave background lensing maps enables a joint calibration of the galaxy-halo connection and the gas fractions of host halos. For the BGS galaxies, we observe low gas fractions around the virial radius relative to standard expectations, likely attributable to active galactic nuclei (AGN) activity. We find some evidence for higher-mass halos retaining a larger fraction of their baryons, consistent with more efficient feedback in lower-mass systems. For the ELG sample, dominated by blue, star-forming galaxies, we provide the first detection of the gas distribution in ELG host halos. The ELGs appear to exhibit relatively high gas fractions, which points to the possibility of weaker feedback (due to, e.g., low AGN and supernova feedback activity) at their mass scale. Finally, we present generalized Navarro-Frenk-White fits to the harmonic-space measurements, providing a compact parametrization of gas profiles for forward modeling in large-scale structure analyses.

We present the most precise measurements of the kinetic Sunyaev-Zel’dovich (kSZ) effect around luminous red galaxies to date, detecting the signal at $18\sigma$ significance in both harmonic and configuration space. Our analysis cross-correlates 2.4 million spectroscopic LRGs from the Dark Energy Spectroscopic Instrument (DESI) DR2 sample with data release 6 (DR6) of the Atacama Cosmology Telescope (ACT). We develop a novel harmonic-space cross-correlation approach using momentum-weighted kSZ templates, yielding nearly uncorrelated bandpowers within a framework consistent with other large-scale structure analyses. By incorporating the LRG halo occupation distribution (HOD) and its uncertainty, we convert measured galaxy gas profiles into halo gas profiles and provide generalized Navarro-Frenk-White (GNFW) fitting profiles, providing empirical targets for tuning feedback efficiency in hydrodynamical simulations and for baryonic modeling in large-scale structure analyses. We find strong evidence that gas profiles do not trace dark matter, providing direct evidence for gas redistribution beyond gravitational collapse. Comparing to hydrodynamical simulations, our measurements favor feedback efficiencies exceeding those in the Battaglia profile, suggesting more efficient gas ejection in group-scale halos than previously predicted. Splitting by redshift, we detect the kSZ signal at $\mathrm{SNR}\approx 5–10$ in each of four bins and find amplitude evolution consistent with the expected decline in mean halo mass at fixed comoving number density. Splitting by stellar mass, we study the scaling of kSZ amplitude with galaxy properties. Together with BGS and ELG measurements in paper II, these results span $0.1\lesssim z\lesssim 1.6$ across three galaxy populations, demonstrating the potential of spectroscopic kSZ to map circumgalactic gas and constrain baryonic feedback.

We compute the classical gravitational Compton amplitude at the fourth post-Minkowskian order, $\mathcal{O}(G^4)$, within the Worldline Quantum Field Theory framework. We derive the associated $N$-matrix element, which provides the gravitational-wave scattering phase shift at the same order. As a nontrivial check, we show that our result agrees with black hole perturbation theory.

We show that all 5D balanced (ADE-shaped) special unitary quivers with no Chern-Simons level admit a UV completion which is a 5D conformal matter superconformal field theory (SCFT). We give explicit local Calabi-Yau threefolds realizing each of these models in M-theory. This unified description enables a systematic exploration of their physical properties, such as their Higgs branch, as well as connections to class-$\mathcal{S}$ constructions and the affine Grassmannian.

Stacking (i.e., averaging) the value of a given astrophysical field around sources allows us to detect new cosmological signatures, such as the kinematic Sunyaev-Zel’dovich, and gain insight on the astrophysical properties of galaxies and their environment. Further information may be gained by orienting these stacks along preferred axes defined by a local directed field, such as the transverse galaxy velocities, galaxy shapes, or the local tidal forces. Examples of this are searches for the moving lens effect, the detection of dipole signatures, or the study of cosmic filaments. Here we show that all directional stacking signals may be reconstructed, without loss of information, in terms of the cross-power spectrum between the quantity of interest and the $E$ and $B$ modes of the spin field used to define the preferred axes weighted by the local galaxy density. The power spectrum approach has several practical advantages, in terms of speed, finite-resolution effects, data visualization, and combination with other cosmological probes. We also argue that, in some cases, such as stacking using velocities or tidal forces reconstructed from the density field, the recovered signal may be dominated by information that is already present in the cross-spectrum between the target field and the galaxy overdensity itself.

As natural telescopes, gravitational lenses enable the observation of sources that would otherwise be too distant and faint. Stellar-mass objects, or microlenses, act as impurities in the lens, producing subtle distortions of the source. These effects are necessary to correctly interpret observations, and may in some cases be themselves evidence of gravitational magnification. Gravitational waves (GWs) observed by ground detectors and magnified by galaxies and clusters will undergo microlensing by fields of stars and remnants: describing these systems requires not only considering a large number of small-scale lenses (microlenses), but also including wave-optics effects, leading to frequency-dependent modulations of the signal. Here we present novel models for reduced-order stochastic diffraction (ROSD), which overcome these challenges in the search for GW lensing signatures: an effective description is synthesized from numerical simulations of wave-optics lensing by stellar fields via a singular value decomposition. The procedure yields an optimized orthonormal basis to describe microlensing distortions—capturing the dominant “tones” of the stellar field, or stellar timbre—and a probability density function for the coefficients, which can be used as priors or to verify the consistency with stellar-field lensing. We present SVD-stellar-I5-aLIGO as an example of this model category, discuss the role of truncation order and demonstrate how it can be applied to GW data via injection and recovery in Bayesian parameter estimation. ROSD can be tailored to account for detector sensitivity and the type of source under analysis, and extended to different microlens populations and external potentials. ROSD models open a new window to probe small-scale objects (stars, remnants and potentially dark matter) and facilitate the discovery of the most distant compact binary mergers.

Coherent elastic neutrino-nucleus scattering ($\mathrm{CE}\nu \mathrm{NS}$) stands out as a pivotal process for precision tests of the Standard Model electroweak sector, investigations of neutrino properties, and searches for new physics. Recent experimental measurements by COHERENT, CONUS+, and ton-scale xenon detectors—including PandaX-4T and XENONnT—underscore the need for a systematic theoretical framework to bridge high-energy physics scenarios with low-energy observational data. In this work, we develop a comprehensive end-to-end effective field theory (EFT) framework for $\mathrm{CE}\nu \mathrm{NS}$, encompassing the complete energy scale hierarchy spanning the ultraviolet regime down to the nuclear sector. We consider the low-energy EFT (LEFT) operators up to dimension 8, incorporating their QCD renormalization-group running effects, and employ the systematic spurion method to achieve matching between these operators and the chiral Lagrangian. A full power counting analysis is performed, extending to nuclear response functions, which evaluates contributions from LEFT operators up to dimension 8 while accounting for the nucleon number enhancement effect intrinsic to $\mathrm{CE}\nu \mathrm{NS}$. Moreover, we match the relevant LEFT operators for $\mathrm{CE}\nu \mathrm{NS}$ onto operators up to dimension 8 within the Standard Model EFT. By also providing their complete tree-level ultraviolet completions, this procedure establishes a consistent top-down theoretical workflow. Leveraging a broad suite of $\mathrm{CE}\nu \mathrm{NS}$ experimental data, this framework enables a combined analysis to extract constraints on the scales of EFT operators and neutrino nonstandard interaction parameters.

We consider a dark sector consisting of fermionic dark matter (DM) charged under a broken dark $U(1{)}_D$ gauge symmetry, interacting with the Standard Model through kinetic mixing. In such models, the DM annihilation cross section is typically suppressed by the small kinetic mixing and or a heavy mediator, often leading to an overabundant relic density. We show that the observed DM abundance can be achieved if the dark Higgs undergoes a strong first order phase transition after DM freeze-out. In this scenario, the relic abundance is set by thermal freeze-out in the symmetric phase and subsequently reduced by entropy injection from the phase transition, rather than by annihilation in the broken phase. We find that to reproduce the observed relic abundance, the required phase transition is generically supercooled. The resulting stochastic gravitational wave signal lies within the sensitivity of future experiments, providing a complementary probe of this framework. Moreover, a strongly supercooled phase transition can potentially account for the NANOGrav signal for DM masses below $O(10)\mathrm{GeV}$.

We present a new analytic model of a force-free electromagnetic jet launched from a disk-fed rotating black hole. The jet solution is force-free to first order in the black hole spin and is obtained through a systematic construction based on previously developed analytical methods. The black hole jet modeled here exhibits an asymptotically parabolic structure and is parametrized by the location of the current concentration and sign reversal on the thin magnetized disk in the equatorial plane. We find that the jet properties show negligible dependence on the disk parameter, suggesting a possible universality of slowly rotating black hole jets with respect to disk structure. Our jet model reproduces the key features expected from the Blandford-Znajek mechanism.

We present an update of our lattice QCD determination of the hadronic contribution to the running of the electromagnetic coupling, $\mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(-Q^2)$, and of the electroweak mixing angle in the spacelike momentum region up to $Q^2=12{\mathrm{GeV}}^2$. The calculation is based on coordinated lattice simulations ensembles with $N_f=2+1$ flavors of $O(a)$-improved Wilson fermions, covering five lattice spacings between 0.039 and 0.085 fm and a range of pion masses, including the physical point. A refined analysis employing a telescopic window strategy allows for a clean separation of systematic effects across Euclidean distance scales. Statistical precision is further enhanced through low-mode averaging, combined with a spectral reconstruction of the vector-vector correlator at long distances on the most chiral ensembles. We confirm significant tensions of up to $7\sigma$ at spacelike virtualities around $Q^2=1{\mathrm{GeV}}^2$ between our lattice results for $\mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(-Q^2)$ and the corresponding data-driven estimates based on $e^{+}{e}^{-}$ cross section data. Combining our lattice data with perturbative QCD via the Euclidean split technique, we obtain at the $Z$ pole $\mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(M_Z^2)=0.027821(34{)}_{\mathrm{lat}}(35{)}_{\text{pQCD}}$, which is more than two times more precise than recent data-driven estimates. Our result deviatesslightly, by $1-2\sigma$, from the value produced by global electroweak fits. For the electroweak mixing angle, we present the hadronic contribution to its running and provide a precise determination of the octet-singlet mixing component ${\overline{\mathrm{\Pi }}}^{(0,8)}$, in good agreement with phenomenological models but with significantly higher precision.

Monoenergetic photons from a pulsed laser diode or LED are commonly used to calibrate the detector response of high-resolution calorimetric detectors. However, when the detector’s resolution is larger than the energy of a single photon, a calibration is normally derived using Poisson statistics. In this paper, we clarify the assumptions implicit in this calibration method, before considering how a more realistic model of a detector’s performance will violate these assumptions, biasing the calibration. Finally, we judge the individual impact of specific detector parameters on our calibration, and conclude with discussion of both the limits of our calculations and the implications for state-of-the art detectors.

We show how equivariant localization can be used to compute the on shell action for supersymmetric $D=5$ anti–de Sitter rotating, charged black holes in theories of supergravity with higher derivatives. An exact match with a dual field theory computation of the superconformal index in a Cardy-like limit is achieved.

We consider high energy scattering in the effective theory of the color glass condensate. The most convenient degrees of freedom are Wilson lines encoding multiple gluon exchanges, whose evolution with energy follows the JIMWLK equation. Instead of using the latter, very often one resorts to a Gaussian approximation (GA), which is known to be remarkably accurate in describing a wide class of multigluon correlators whose expansion in the weak scattering limit starts with an exchange of only two gluons. Here we demonstrate, both analytically and numerically, that such an approximation is not valid for correlators which start with an exchange of four gluons. As a main example, we focus on incoherent diffraction in photon-nucleus collisions and we show that the discrepancy between the JIMWLK and the GA results is driven by weak scattering and further persists in the regime where unitarity corrections begin to become important. The JIMWLK calculation leads to cross sections which are systematically larger in all kinematic regimes of interest.

A terrestrial population of millicharged particles that interact significantly with normal matter can arise if they make up a dark matter subcomponent or if they are light enough to be produced in cosmic-ray air showers. Such particles thermalize to terrestrial temperatures through repeated scatters with normal matter in Earth’s environment. We show that a simple electrified shell (for example, a Van de Graaff generator) functions as an efficient accumulator of such room-temperature millicharged particles, parametrically enhancing their local density by as much as 12 orders of magnitude. This can be used to boost the sensitivity of any detector housed in the shell’s interior, such as ion traps and tests of Coulomb’s law. In a companion paper, we apply this specifically to Cavendish tests of Coulomb’s law, and we show that a well-established setup can probe a large region of unexplored parameter space, with sensitivity to the irreducible density of millicharged particles generated from cosmic rays that outperforms future accelerator searches for sub-GeV masses.

The gluon emission from an energetic heavy quark is suppressed in the forward direction below the angle $\mathrm{\Theta }\lesssim m_Q/E$ for a quark of mass $m_Q$ and energy $E$ according to perturbative quantum chromodynamics (QCD) (“dead cone”). Another consequence is the suppression of energetic particles in the jet, which has been observed already for $c$- and $b$-quark jets. The suppression of the forward particles can be explained by an application of the modified leading logarithmic approximation of perturbative QCD. In this paper, we investigate whether this type of analysis can be carried out also for top-quark jets with a much higher heavy-quark mass allowing for QCD tests in this new kinematic regime. The new aspect of this analysis is the finite lifetime of the top quark. We consider for simplicity the decay $t\to b\ell \nu$, where the $b$ quark radiates gluons as well and partially obscures the dead cone. Guided by the decay amplitude in leading order in ${\alpha }_s$ for $e^{+}{e}^{-}\to t\overline{t}$, we propose a method to separate the radiation by the $\widehat{tb}$ dipole in the decay process, which is superimposed on the primary radiation from the $\widehat{t\overline{t}}$ dipole involving the top-quark dead-cone effect. The momentum distributions of partons or hadrons are determined for finite decay angles of the $b$-quark ${\mathrm{\Theta }}_b$ and extrapolated in the forward direction ${\mathrm{\Theta }}_b=0$ where the radiation from the decay process is expected to vanish. This method is successfully tested at the parton level, and the results obtained for hadrons are compatible with the modified leading logarithmic approximation relation with an accuracy of around 15%. Our calculations are carried out with the pythia 8.3 Monte Carlo event generator.

Next-generation neutrino oscillation experiments such as the Deep Underground Neutrino Experiment require percent-level knowledge of neutrino-nucleon interaction cross sections. The nucleon axial form factor $F_A(Q^2)$, parametrized by the axial mass $M_A$, is the dominant source of uncertainty in the quasielastic channel, and the parity-violating structure function $x{F}_3$ is poorly constrained on free nucleons. We propose using charged-current (CC) electron-proton scattering at the Electron-Ion Collider (EIC) to address both problems simultaneously. The measurement exploits three key features of the EIC: (1) helicity-selective electron bunches provide in situ electromagnetic background rejection; (2) a longitudinally polarized proton target enables extraction of $F_A(Q^2)$ through the target-spin asymmetry $A_{UL}$; and (3) the $y$-distribution leverage in CC deep inelastic scattering (DIS) separates $F_2$ and $x{F}_3$ on a free proton, without nuclear corrections. Using a Fisher information analysis at $\sqrt{s}=141\mathrm{GeV}$ with $500{\mathrm{fb}}^{-1}$ of integrated luminosity, we project the Cramér-Rao statistical floor of $\delta M_A\approx 0.03\mathrm{GeV}$ (3%). Incorporating first-order realistic detector effects, such as zero-degree calorimeter acceptance, $Q^2$ smearing (5%), and background noise from helicity subtraction, the projected sensitivity is severely background-limited due to the small signal-to-background ratio ($S/B\approx 3\times {10}^{-4}$) in the elastic channel. Achieving competitive sensitivity ($\delta M_A\approx 0.14\mathrm{GeV}$) would require $\sim {10}^{-7}$ background suppression, 3 orders of magnitude beyond current projections. The CC DIS $y$ distribution provides subpercent extraction of $x{F}_3^{W^{-}}$ over $0.05<x<0.5$, representing the most robust electroweak measurement in the near term.

The nonrelativistic string spectrum is built from integer-spaced energy quanta in such a way that the high-temperature asymptotics, via the Hardy-Ramanujan formula for integer partitions, reduces to standard two-dimensional thermodynamics. Here we explore deformed realizations of this behavior motivated by $p$-adic string theory and Lorentzian versions thereof with a nontrivial spectrum. We study the microstate scaling that results on associating quantum harmonic oscillators to the normal modes of tree graphs rather than string graphs and observe that Hardy-Ramanujan scaling is not realized. But by computing the eigenvalues of the derivative operator on the $p$-adic circle and by determining the eigenspectrum of the Neumann-to-Dirichlet operator, we uncover a spectrum of exponentially growing energies but with exponentially growing degeneracies balanced in such a way that Hardy-Ramanujan scaling is realized, but modulated with log-periodic fluctuations.

A new tension is emerging between the tight cosmological upper bounds on the total neutrino mass ($\sum m_{\nu }\lesssim 0.06\mathrm{eV}$) and the lower limits from oscillation experiments, with potentially far-reaching implications for cosmology and particle physics. Neutrinos decaying into massless Beyond the Standard Model (BSM) particles with lifetimes ${\tau }_{\nu }\sim 0.01–1\mathrm{Gyr}$ represent a theoretically well-motivated mechanism to reconcile such measurements. Using Dark Energy Spectroscopic Instrument Data Release 2 and cosmic microwave background datasets, we show that such invisible decays relax the bound on the total neutrino mass up to $\sum m_{\nu }<0.23\mathrm{eV}$ (95%), restoring full agreement with oscillation data. We also present the first late-time cosmological analysis of invisible neutrino decays into lighter neutrinos in a manner consistent with the measured mass splittings. In contrast to the decays into massless BSM particles, we find that this scenario only marginally alleviates—or even tightens—the cosmological neutrino mass bounds, depending on the mass ordering.