Magnetic fields between a supernova (SN) and Earth convert axions into gamma rays. The absence of such a signal in coincidence with SN 1987A neutrinos, using the coherent Milky Way field, provides well-studied constraints on $g_{ap}\times g_{a\gamma }$ (axion-proton times axion-photon couplings) and on $g_{a\gamma }$ alone. We sh…

[Phys. Rev. Lett. 137, 121002] Published Tue Sep 15, 2026

The observation of a binary pulsar system characterized by low neutron star masses with short orbital period enables tests of relativity, and may enable a measurement of Lens-Thirring precession with future observations.

[Phys. Rev. Lett. 137, 121401] Published Tue Sep 15, 2026

We present greyring, a new model for the postmerger signal in black-hole binary coalescences based on the graybody factor of the remnant. The model accurately reproduces the full frequency-domain ringdown signal for a large set of comparable-mass, aligned-spin numerical relativity waveforms, includi…

[Phys. Rev. Lett. 137, 121402] Published Tue Sep 15, 2026

We report on a search for sub-GeV dark matter upscattered via the solar reflection mechanism in the heavy mediator scenario. Under the standard halo model, keV–MeV dark matter produces nuclear recoils with energies below the detection threshold of liquid xenon time projection chambers. We enhance se…

[Phys. Rev. Lett. 137, 121001] Published Mon Sep 14, 2026

We propose a novel strategy to probe feebly interacting particles (FIPs) by exploiting the dense, confined circumstellar medium (CSM) surrounding core-collapse supernovae. FIPs produced in the protoneutron star can deposit substantial visible energy into the CSM via decay prior to the shock breakout…

[Phys. Rev. Lett. 137, 111005] Published Fri Sep 11, 2026

Even 50 years after the discovery of a positron annihilation line from the inner Galaxy, no class of astrophysical sources has emerged as a definitive explanation for both the emission morphology and flux. Positrons produced by dark matter annihilation or decay have been proposed, but the mass of an…

[Phys. Rev. Lett. 137, 111003] Published Wed Sep 09, 2026

We propose a new mechanism for the formation of seeds of supermassive black holes at early cosmic epochs. Our scenario explores density fluctuations that are enhanced relative to $\mathrm{\Lambda }\mathrm{CDM}$ expectations, but with amplitudes that are not large enough to form primordial black holes, and that can still lead …

[Phys. Rev. Lett. 137, 111004] Published Wed Sep 09, 2026

We compute the gravitational interaction of two coalescing compact objects at sixth post-Newtonian order in the static limit, employing the diagrammatic approach within the effective field theory framework of general relativity. The calculation requires the evaluation of six-loop Feynman diagrams th…

[Phys. Rev. Lett. 137, 111401] Published Wed Sep 09, 2026

Quantum gravity theories often modify spacetime symmetries. In particular, Lorentz invariance may be violated when approaching the Planck scale. Although the scales at which interactions occur in extensive air showers induced by ultra-high-energy cosmic rays in the atmosphere are many orders of magn…

[Phys. Rev. Lett. 137, 111001] Published Tue Sep 08, 2026

A photon at $\mathcal{E}\simeq 251\mathrm{TeV}$ from GRB 221009A was detected by the Carpet Collaboration in 2022 using a partial dataset. Very recently, Carpet has completed its full data analysis reporting further support for its previous photon now at $\mathcal{E}=300_{-38}^{+43}\mathrm{TeV}$. Within standard propagation models, this observation…

[Phys. Rev. Lett. 137, 111002] Published Tue Sep 08, 2026

The standard lambda cold dark matter cosmological model predicts that cosmic filaments are highly clumpy, whereas warm dark matter—invoked to address small-scale challenges in the lambda cold dark matter model—produces filaments that are noticeably smoother and less structured. In this Letter, we in…

[Phys. Rev. Lett. 137, 101002] Published Fri Sep 04, 2026

Recent advancements in small-scale observations of the cosmic microwave background have provided a unique opportunity to characterize the distribution of baryons in the outskirts of galaxies via stacking-based analyses of the kinetic Sunyaev-Zel’dovich effect. Such measurements, mathematically equiv…

[Phys. Rev. Lett. 137, 101001] Published Thu Sep 03, 2026

The emergence of the $r=0$ singularity inside a spherically symmetric charged black hole is studied numerically within the Einstein-Maxwell-real scalar model. When the scalar field reaches a critical strength, the $r=0$ singularity emerges inside the black hole at the tip of the causal diamond. By varyi…

[Phys. Rev. Lett. 137, 101401] Published Tue Sep 01, 2026

The $\mathrm{\Lambda }$ cold dark matter cosmological model faces increasingly significant and robust tensions among independent cosmological probes, prompting renewed scrutiny of its foundational assumptions. While general relativity and the nature of darkenergy are now routinely tested with cosmological surveys, le…

[Phys. Rev. Lett. 137, 091001] Published Thu Aug 27, 2026

A 500-hour survey of the Galactic Center by the H.E.S.S. telescope array has set the most stringent limits to date on TeV dark matter line annihilation cross sections.

[Phys. Rev. Lett. 137, 091002] Published Thu Aug 27, 2026

In the presence of a weak gravitational wave (GW) background, astrophysical binary systems act as high-quality resonators, with efficient transfer of energy and momentum between the orbit and a harmonic GW leading to potentially detectable orbital perturbations. In this Letter, we develop and apply …

[Phys. Rev. Lett. 137, 091401] Published Mon Aug 24, 2026

Using the worldline quantum field theory formalism, we compute conservative contributions to the scattering angle and impulse for classical black hole scattering at fifth post-Minkowskian and second self-force order. This four-loop calculation involves nonplanar Feynman integrals and requires advanc…

[Phys. Rev. Lett. 137, 081402] Published Fri Aug 21, 2026

The flavor composition of cosmic neutrinos probes both the physical properties of their sources and oscillations over energies and distances unreachable by terrestrial experiments. Using 11.4 yr of IceCube data, we analyze the flavor composition of the all-sky neutrino flux from 5 TeV–10 PeV, signif…

[Phys. Rev. Lett. 137, 081002] Published Tue Aug 18, 2026

We present observational constraints on large-scale white noise (LSWN) in the cosmic density field, a phenomenon predicted to arise from nonlinear mode coupling during cosmological evolution. Building on the theoretical framework of our companion paper, where we demonstrated that nonlinearities inev…

[Phys. Rev. Lett. 137, 081003] Published Tue Aug 18, 2026

The formation of gravitationally bound overdensities of dark matter (DM), or halos, is a generic prediction of theories with particle DM. We present a measurement of halo properties in 28 quadruple image strong lens systems recently observed by JWST, and use these observations to constrain the free-…

[Phys. Rev. Lett. 137, 081004] Published Tue Aug 18, 2026

The frequency-domain waveform emitted by a two-body scattering process is computed in the extreme-mass-ratio limit through the fifth post-Minkowskian (PM) order [i.e., $O(G^5)$] and the fractional sixth post-Newtonian (PN) order. The current accuracy of the scattering waveform obtained by quantum ampli…

[Phys. Rev. Lett. 137, 081401] Published Tue Aug 18, 2026

Exotic spin-spin-velocity-dependent interactions, predicted in extensions of the standard model involving new bosonic fields, could resolve fundamental puzzles from dark matter to cosmic asymmetry. However, exploring these weak potential interactions at centimeter scales presents formidable challeng…

[Phys. Rev. Lett. 137, 081001] Published Mon Aug 17, 2026

A model that captures how crater-forming impacts redistribute lunar dirt will help researchers read the cosmic timeline found in samples returned from the Moon.

[Phys. Rev. Lett. 137, 071005] Published Fri Aug 14, 2026

Several theoretical proposals describe horizonless compact objects that can mimic black holes in their gravitational wave signatures; however, their spin-induced quadrupole moments (SIQMs) may reveal their distinct nature. Using the tight bounds on the SIQM of GW241011, we place constraints on the n…

[Phys. Rev. Lett. 137, 071402] Published Fri Aug 14, 2026

We revisit and invalidate all dark photon dark matter constraints from resonant conversion of dark photons into photons (plasmons) in the early universe. These constraints rely on the resonant transfer of a substantial portion of the dark photon energy density into the SM plasma, heating the plasma …

[Phys. Rev. Lett. 137, 071004] Published Thu Aug 13, 2026

GW240925 and GW250207 are two loud gravitational-wave signals from binary black hole coalescences observed with network signal-to-noise ratios $\sim 32$ and $\sim 69$, respectively, by the LIGO Hanford-LIGO Livingston-Virgo network. Gravitational-wave signals from coalescing binaries have characteristic phase a…

[Phys. Rev. Lett. 137, 071401] Published Thu Aug 13, 2026

As the largest gravitationally bound objects in the Universe, galaxy clusters have provided the first piece of evidence for the presence of dark matter and may be suitable targets for indirect dark matter searches. Among various signals, the GeV-TeV $\gamma$-ray line has been taken as the smoking-gun signa…

[Phys. Rev. Lett. 137, 071003] Published Wed Aug 12, 2026

We explore the lowest mass limit that can be placed on the halo mass function in cold dark matter (CDM) using 28 strong gravitational lenses. For this purpose, we study an extreme model in which the halo mass function and mass-concentration relation follow CDM, with a sharp cutoff at some mass scale…

[Phys. Rev. Lett. 137, 071001] Published Tue Aug 11, 2026

I present a new indirect search for dark matter (DM) using hydrogen-$\alpha$ ($\mathrm{H}\alpha$) recombination emission. DM annihilation or decay products can ionize neutral gas; subsequent recombination cascades generate $\mathrm{H}\alpha$ photons through the $3\to 2$ transition. In quiet gas-rich dwarf galaxies, the $n=2$ population is negli…

[Phys. Rev. Lett. 137, 071002] Published Tue Aug 11, 2026

Recent pulsar timing array (PTA) analyses show evidence for a gravitational wave background (GWB) with angular correlations consistent with the Hellings-Downs curve. Anisotropies are a key discriminator of the origin of this GWB, as they are expected to be at 1%–20% for astrophysical sources, but su…

[Phys. Rev. Lett. 137, 061003] Published Thu Aug 06, 2026

Supernova (SN) 1987A provides classic bounds on gamma-ray flashes from the radiative decay of sub-GeV particles, but the latter may decay so rapidly as to be shielded by the stellar envelope. Using axionlike particles with photon coupling as a benchmark, we show that Type Ic core-collapse supernovae…

[Phys. Rev. Lett. 137, 061004] Published Thu Aug 06, 2026

The primordial power spectrum of matter density perturbations contains highly valuable information about new fundamental physics, in particular cosmological inflation, but is only very weakly constrained observationally for small cosmological scales $k\gtrsim 3{\mathrm{Mpc}}^{-1}$. We derive novel constraints, ${\mathcal{P}}_{\mathcal{R}}(k)\lesssim 5\times {\mathrm{1\dots }}^{}$

[Phys. Rev. Lett. 137, 061002] Published Tue Aug 04, 2026

We have made measurements of the difference between the position angle (PA) on the sky and the polarization position angle (PPA) of radio sources using data from a combination of the Radio Fundamental Catalogue (RFC) across a range of frequencies between 2.7 and 15 GHz and Cosmic Lens All-Sky Survey…

[Phys. Rev. Lett. 137, 061001] Published Mon Aug 03, 2026

World-leading bounds are placed on sub-keV axionlike and dark-photon dark matter using ionization-only data from a liquid xenon detector.

[Phys. Rev. Lett. 137, 051003] Published Thu Jul 30, 2026

Small deviations from isotropy in the arrival directions of Galactic cosmic rays serve as a unique probe of the local magnetic environment. In this Letter, we report observations of medium-scale anisotropies at energies above 10 TeV using the LHAASO-KM2A array. Our analysis identifies four regions o…

[Phys. Rev. Lett. 137, 051004] Published Thu Jul 30, 2026

Nickel, one of the most tightly bound nuclei alongside iron, is the most abundant heavy element beyond iron in cosmic rays. With DAMPE’s excellent charge resolution and broad energy range, a high-precision energy spectrum provides valuable insights into the acceleration sources of heavy nuclei and t…

[Phys. Rev. Lett. 137, 051001] Published Tue Jul 28, 2026

A first-order phase transition could occur in the late Universe when vacuum energy begins dominating the energy density ($z\lesssim 0.3$) and convert some latent heat into other forms such as invisible radiation. This generic possibility also has concrete motivation in particle physics models, which invoke a …

[Phys. Rev. Lett. 137, 051002] Published Tue Jul 28, 2026

We perform fully relativistic general-relativistic magnetohydrodynamics simulations of magnetized, self-gravitating black hole disk (BHD) systems in which the black hole spin is misaligned with the disk angular momentum. Massive disks (disk to black hole mass ratios of 16%–28%) around rapidly rotati…

[Phys. Rev. Lett. 137, 051402] Published Tue Jul 28, 2026

We analyze the expectation value of the energy-momentum tensor and its fluctuations in quantum field theory on curved spacetimes. A generally accepeted condition for the conceptual consistency of semiclassical gravity is that the fluctuations of the energy momentum tensor remain small compared to it…

[Phys. Rev. Lett. 137, 051501] Published Tue Jul 28, 2026

Violations of Lorentz invariance, a cornerstone of modern physics, are predicted by theories of quantum gravity and by extensions of general relativity involving new vector or tensor fields. In the weak-field limit, such a violation would primarily manifest as a nonzero value for the post-Newtonian …

[Phys. Rev. Lett. 137, 051401] Published Mon Jul 27, 2026

The dispersion of extragalactic fast radio bursts (FRBs) can serve as a powerful probe of the diffuse plasma between and surrounding galaxies, which contains most of the Universe’s baryons. By cross-correlating the dispersion of background FRBs with the locations of foreground galaxies, we can study…

[Phys. Rev. Lett. 137, 041001] Published Tue Jul 21, 2026

Orbital eccentricity is a key tracer of the astrophysical origins of compact binaries; yet it remains absent from routine LIGO-Virgo-KAGRA analyses, in part because of the prohibitive computational cost of generating eccentric template waveforms. The complicated morphology of these waveforms due to …

[Phys. Rev. Lett. 137, 041401] Published Tue Jul 21, 2026

In 2023, after more than two decades of searching, pulsar timing array (PTA) collaborations around the world announced evidence for a stochastic gravitational wave background. It was quickly followed by work from the International Pulsar Timing Array (IPTA), demonstrating that the results of regiona…

[Phys. Rev. Lett. 137, 041402] Published Tue Jul 21, 2026

We construct a simple two-dimensional holographic model of a closed “baby” universe. The baby universe spacetime originates from the black hole interior in Jackiw-Teitelboim gravity. The holographic description is a low-temperature thermal pure state of two Sachdev-Ye-Kitaev (SYK) models. The constr…

[Phys. Rev. Lett. 137, 041501] Published Mon Jul 20, 2026

We show that oscillating (real-scalar) boson stars generically host an oscillating radial caustic. Sources near this caustic cross it every half period, thereby producing periodic caustic-crossing lensing. The resulting observables are phase locked to the lens oscillation: image-pair creation or ann…

[Phys. Rev. Lett. 137, 031403] Published Fri Jul 17, 2026

Using a combination of Hubble Space Telescope and James Webb Space Telescope imaging, a runaway supermassive black hole was recently identified with an inferred velocity of ${954}_{-126}^{+110}\mathrm{km}{\mathrm{s}}^{-1}$, likely ejected from a compact star-forming galaxy at $z\approx 0.96$. Assuming the runaway black hole originated fr…

[Phys. Rev. Lett. 137, 031404] Published Fri Jul 17, 2026

Extending the sensitivity of terrestrial gravitational-wave detectors below 20 Hz is a long-standing challenge, limited by ground motion and inertial sensing noise. In this Letter, we demonstrate ultra-high-vacuum compatible inertial isolation and position sensing technologies that achieve active pl…

[Phys. Rev. Lett. 137, 031401] Published Thu Jul 16, 2026

IGR J17480-2446 is a low-mass x-ray binary, harboring an exceptional accreting pulsar (a neutron star) with an unusual spin frequency of 11 Hz and a very slow postoutburst crust cooling. The former may imply that it is observed at an early stage of recycling, while the latter was shown to indicate t…

[Phys. Rev. Lett. 137, 031402] Published Thu Jul 16, 2026

We show that the canonical formulation of the semiclassical Einstein equation, where the matter terms in the constraints are replaced by expectation values of the corresponding operators in quantum states, is inconsistent due to the nonclosure of the resulting constraint algebra.

[Phys. Rev. Lett. 137, 031501] Published Thu Jul 16, 2026

We introduce accelerated sequential posterior inference via reuse (ASPIRE), a broadly applicable framework that transforms existing posterior samples and Bayesian evidence estimates into unbiased results under alternative models without rerunning the original analysis. ASPIRE combines normalizing fl…

[Phys. Rev. Lett. 137, 021410] Published Fri Jul 10, 2026

A proposed gravitational-wave observatory on the Moon might gather more information than previously thought, thanks to geology.

[Phys. Rev. Lett. 137, 021408] Published Thu Jul 09, 2026

A proposed gravitational-wave observatory on the Moon might gather more information than previously thought, thanks to geology.

[Phys. Rev. Lett. 137, 021409] Published Thu Jul 09, 2026

We propose a quantum-error-correction-inspired noise mitigation protocol for enhancing the sensitivity of wavelike dark matter searches with quantum sensors. Our protocol uses multiple sensors to mitigate the noise affecting each sensor individually, allowing for the suppression of excitation noise …

[Phys. Rev. Lett. 137, 021001] Published Wed Jul 08, 2026

Gravitational-wave signals are typically interpreted under the vacuum hypothesis, i.e., assuming negligible influence from the astrophysical environment. This assumption is expected to break down for low-frequency sources such as extreme mass ratio inspirals (EMRIs), which are prime targets for the …

[Phys. Rev. Lett. 137, 021405] Published Tue Jul 07, 2026

The remnant properties of black hole mergers may be governed by a maximum entropy bound suggesting that once the black holes become sufficiently close together, the throat around both black holes resembles that of an individual Kerr black hole to a far-away observer, and thus the Kerr entropy computation becomes valid.

[Phys. Rev. Lett. 137, 021406] Published Tue Jul 07, 2026

The active galactic nucleus (AGN) accretion disks are ideal sites for hierarchical black hole (BH) mergers. To robustly probe such a possibility, we analyze binary black hole mergers in the GWTC-4 with a flexible mixture population model for component masses, spin magnitudes, and spin tilt angles, a…

[Phys. Rev. Lett. 137, 021407] Published Tue Jul 07, 2026

We study the scattering of two boson stars by comparing four sequences (at fixed energy and varying impact parameter) of numerical relativity simulations to an effective-one-body analytic description, taking into account both gravitational effects (point-mass and tidal) and short-range scalar-field …

[Phys. Rev. Lett. 137, 021401] Published Mon Jul 06, 2026

We compute the complete potential-graviton contributions to the conservative radial action and scattering angle for two nonspinning bodies in general relativity, accurate through fifth order in Newton’s constant and including second-order self-force effects. The calculation is carried out in the sca…

[Phys. Rev. Lett. 137, 021402] Published Mon Jul 06, 2026

Different analyses of gravitational-wave observations are converging on evidence for a distinct population of massive black hole binaries produced through repeated mergers.

[Phys. Rev. Lett. 137, 021403] Published Mon Jul 06, 2026

Different analyses of gravitational-wave observations are converging on evidence for a distinct population of massive black hole binaries produced through repeated mergers.

[Phys. Rev. Lett. 137, 021404] Published Mon Jul 06, 2026

Scattering between dark matter (DM) and protons leads to suppressed small-scale fluctuations, with implications for a variety of cosmological observables. In this Letter, we search for evidence of DM-proton scattering with an interaction cross section $\sigma ={\sigma }_0(v/c{)}^n$ for $n=0$, 2 and 4, corresponding, e.g.…

[Phys. Rev. Lett. 137, 011001] Published Tue Jun 30, 2026

The James Webb Space Telescope (JWST) has discovered bright galaxies at high redshifts ($z\approx 10–14$) and various galaxy candidates extending to even higher redshifts ($z\approx 15–30$). Many astrophysical and beyond the Standard Model physics scenarios have been proposed to explain these observations. We investi…

[Phys. Rev. Lett. 137, 011002] Published Tue Jun 30, 2026

A solar storm hitting Earth appears to have reduced the amount of incoming high-energy cosmic rays, suggesting a new way of measuring solar activity.

[Phys. Rev. Lett. 136, 251002] Published Fri Jun 26, 2026

We point out that dark matter (DM) can illuminate planetary skies via ultraviolet airglow. Dark matter annihilation products can excite molecular hydrogen, which then deexcites to produce ultraviolet emission in the Lyman and Werner bands. We search for this new effect by analyzing nightside ultravi…

[Phys. Rev. Lett. 136, 251001] Published Thu Jun 25, 2026

A modular framework within the self-force formalism that applies to a large class of effective field theories of gravity in order to perform tests of general relativity with binary black hole mergers is critical for tests of general relativity that make use of the upcoming space-based gravitational wave detectors such as LISA.

[Phys. Rev. Lett. 136, 251404] Published Wed Jun 24, 2026

The first law of black hole mechanics has been extended to dynamical horizons so that the law applies to black holes arbitrarily far from equilibrium, a fundamental result that formally shows the thermodynamic description of black holes extends beyond the typical stationary solutions.

[Phys. Rev. Lett. 136, 251405] Published Wed Jun 24, 2026

Gravitational-wave data analysis relies on accurate and efficient methods to extract physical information from noisy detector signals, yet the increasing rate and complexity of observations represent a growing challenge. Deep learning provides a powerful alternative to traditional inference, but exi…

[Phys. Rev. Lett. 136, 251401] Published Tue Jun 23, 2026

We study the nonlinear interior dynamics of spontaneously scalarized black holes in Einstein-Maxwell-scalar theory with zero cosmological constant, revealing novel critical phenomena. We demonstrate that, for a wide range of scalar-electromagnetic couplings, scalarized black holes possess no smooth …

[Phys. Rev. Lett. 136, 251402] Published Tue Jun 23, 2026

We consider the string-theory-inspired Einstein-Maxwell-Maxwell-dilaton theory and show that we can derive the complete set of thermodynamic quantities of charged black holes without having to construct the black hole solutions. We argue that the technique can be applied more broadly to string theor…

[Phys. Rev. Lett. 136, 251403] Published Tue Jun 23, 2026

We study the dynamics of the Bianchi I universe in modified loop quantum cosmology (mLQC-I) and uncover a robust mechanism for isotropization: the shear is dynamically suppressed after the bounce and decays rapidly in the quantum postbounce regime, independently of the equation of state of standard …

[Phys. Rev. Lett. 136, 251501] Published Tue Jun 23, 2026

We propose a novel strategy and a new class of detectors for the direct detection of axion dark matter in the meV mass range, based on resonantly enhanced axion-photon conversion through the inverse Primakoff effect in engineered radiometers composed of quantum semiconductor heterostructures. Semico…

[Phys. Rev. Lett. 136, 241001] Published Thu Jun 18, 2026

We report the unique properties of cosmic phosphorus (P), chlorine (Cl), argon (Ar), potassium (K), and calcium (Ca) fluxes in the GV to TV rigidity range collected by the Alpha Magnetic Spectrometer (AMS) on the International Space Station. With a total of one million events collected over 13.5 yea…

[Phys. Rev. Lett. 136, 241002] Published Wed Jun 17, 2026

The leading corrections to general relativity can be parametrized by higher-derivative interactions in a low-energy effective field theory, in a way that is general and agnostic to the precise UV completion of gravity. Using numerical methods, we compute the leading-order corrections to the Kerr met…

[Phys. Rev. Lett. 136, 241401] Published Tue Jun 16, 2026

The Galactic Center Excess (GCE) may yet herald the discovery of annihilating dark matter. Weighing against that conclusion are analyses showing evidence for dim point sources within the spatial structure of the emission. Because of technical limitations these analyses are purely spatial with all sp…

[Phys. Rev. Lett. 136, 231001] Published Fri Jun 12, 2026

The James Webb Space Telescope has uncovered a population of compact, high-redshift sources, the Little Red Dots (LRDs), which may host supermassive black holes (BHs) significantly heavier than their stellar content compared with local scaling relations. These objects challenge standard models of ea…

[Phys. Rev. Lett. 136, 231402] Published Fri Jun 12, 2026

It is shown that the Kerr metric represents the nonlinear superposition of self-dual and anti-self-dual Taub-Newman-Unti-Tamburino (NUT) instantons. This promotes the Newman-Janis algorithm to a rigorous derivation of the Kerr metric with a definite physical origin. In the same way, the Kerr-Newman …

[Phys. Rev. Lett. 136, 231401] Published Tue Jun 09, 2026

We show that general relativity and other geometrical theories can be viewed as a degenerate Otto cycle with only heat-exchange legs in emergent gravity. Including work-producing legs yields controlled violations of local Lorentz invariance and energy-momentum conservation, which produce late-time c…

[Phys. Rev. Lett. 136, 231501] Published Mon Jun 08, 2026

The ambiguity in associating gravitational waves with transverse-traceless components of the metric at second order in perturbation theory is resolved by computing the detector response to second order for the first time.

[Phys. Rev. Lett. 136, 221402] Published Wed Jun 03, 2026

For a quantum field of arbitrary mass and spin in the static patch of de Sitter spacetime, the Euclidean partition function receives contributions from edge modes localized on the horizon, expressible in terms of the Harish-Chandra character of the de Sitter group. Considering the flat limit and sum…

[Phys. Rev. Lett. 136, 221501] Published Wed Jun 03, 2026

In this Letter, we provide a novel test of general relativity based on ringdown analysis. The test is performed on agnostic models, where the postmerger signal is fitted with a superposition of damped sinusoids. If at least two modes are detected, one has to compute the ratio of the frequencies and …

[Phys. Rev. Lett. 136, 221401] Published Mon Jun 01, 2026

Dark matter particles with sufficiently large interactions with ordinary matter can scatter in the Earth’s atmosphere and crust before reaching an underground detector. This Earth-shielding effect can induce a directional dependence in the dark matter flux, leading to a sidereal daily modulation in …

[Phys. Rev. Lett. 136, 211001] Published Wed May 27, 2026

We explicitly construct the density matrix associated to the vacuum state of a large spherically symmetric causal diamond of area $A$ in four-dimensional asymptotically flat gravity. We achieve this using the soft effective action, which characterizes the low-energy gravitational degrees of freedom th…

[Phys. Rev. Lett. 136, 211501] Published Wed May 27, 2026

We construct a novel effective field theory for a compact body coupled to gravity, whose key feature is that the dynamics of gravitational perturbations is explicitly determined by known solutions in black hole perturbation theory in four dimensions. In this way, the physics of gravitational perturb…

[Phys. Rev. Lett. 136, 211401] Published Tue May 26, 2026

GW231123, the heaviest binary black hole merger detected by the LIGO-Virgo-KAGRA Collaboration to date, lies in the pair-instability mass gap and exhibits unusually high component spins. In this Letter, we show that both merging black holes may have a primordial origin with smaller initial masses. T…

[Phys. Rev. Lett. 136, 201401] Published Thu May 21, 2026

We propose a novel coherent freeze-out mechanism where a weakly interacting massive particle (WIMP) is quadratically coupled to a light axionlike particle (ALP). Although the coupling is too feeble to thermalize the ALP, coherent forward scattering induces medium-dependent mass shifts that significa…

[Phys. Rev. Lett. 136, 201004] Published Wed May 20, 2026

We study an $\mathrm{O}(N)$ scalar multiplet nonminimally coupled to gravity and follow its renormalization-group (RG) flow in the vicinity of an interacting, nonperturbatively UV-complete scaling regime of scalar-tensor theory. In the broken phase, the radial mode mediates a universal Yukawa correction to New…

[Phys. Rev. Lett. 136, 201501] Published Wed May 20, 2026

Dark matter (DM) models with a conserved particle-antiparticle number, $n_{\chi }-n_{\tilde{\chi }}$, and the asymmetry in the cosmological abundance $n_{\chi }\ne n_{\tilde{\chi }}$, are known to be challenged by the existence of old neutron stars (NSs), as the sufficient accumulation of DM will lead to the collapse of NSs into black holes. We de…

[Phys. Rev. Lett. 136, 201002] Published Tue May 19, 2026

We introduce a novel class of bosonic dark matter candidates that we dub wallions, featuring boundaries in field space. The wallion mass is exponentially suppressed when the separation between boundaries far exceeds their intrinsic width and remains radiatively stable under self-interactions. We stu…

[Phys. Rev. Lett. 136, 201003] Published Tue May 19, 2026

We discuss a modification of a recently developed numerical scheme for evolving spherically symmetric self-gravitating systems to include the effects of self-interacting dark matter. The approach is far more efficient than traditional $N$-body simulations and cross sections with different dependencies…

[Phys. Rev. Lett. 136, 201001] Published Mon May 18, 2026

We present a fully Bayesian, data-driven framework for identifying quasinormal modes in high-accuracy Cauchy characteristic evolution gravitational waveforms. Applying this to a public catalog, we identify quasinormal mode overtones, retrograde modes, and nonlinear modes up to cubic order in the rin…

[Phys. Rev. Lett. 136, 191403] Published Wed May 13, 2026

We demonstrate that the phase space of the soft sector of asymptotically flat gravity in four spacetime dimensions can be identified with that of a spherically symmetric finite casual diamond in Minkowski spacetime. The leading soft graviton mode is geometrically identified with the radial fluctuati…

[Phys. Rev. Lett. 136, 191501] Published Wed May 13, 2026

Discretely self-similar solutions govern critical collapse and have been known only numerically since Choptuik’s pioneering work. Using the large-$D$ expansion, where $D$ is the spacetime dimension, we construct an infinite family of analytic solutions of the Einstein-massless-Klein-Gordon equations. In…

[Phys. Rev. Lett. 136, 191401] Published Tue May 12, 2026

Light scalar particles arise naturally in many extensions of the standard model and are compelling dark-matter candidates. Gravitational interactions near black holes can trigger the growth of dense scalar configurations that, if sustained during inspiral, alter binary dynamics and imprint signature…

[Phys. Rev. Lett. 136, 191402] Published Tue May 12, 2026

We conduct an indirect dark matter (DM) search in the vicinity of the Galactic Center, focusing on a square region within $\pm 9°$ in Galactic longitude and latutide, using 2865 days of data ($\sim 8\mathrm{yr}$) from the High-Altitude Water Cherenkov (HAWC) Observatory. We explore DM particles within the weakly inte…

[Phys. Rev. Lett. 136, 191001] Published Mon May 11, 2026

By incorporating a detailed model of neutrino-flavor oscillations in simulations of collapsing stars, researchers have shown that the phenomenon can both promote and inhibit supernovae.

[Phys. Rev. Lett. 136, 191002] Published Mon May 11, 2026

We investigate the propagation of ultraheavy (UH) nuclei as ultrahigh-energy cosmic rays (UHECRs). We show that their energy loss lengths at $\lesssim 300\mathrm{EeV}$ are significantly longer than those of protons and intermediate-mass nuclei, and that the highest-energy cosmic rays with energies beyond $\sim 100\mathrm{EeV}$, …

[Phys. Rev. Lett. 136, 181002] Published Thu May 07, 2026

The observation of ultrahigh-energy radiation from a binary star system suggests that such “gamma-ray binaries” could be significant contributors to the cosmic-ray spectrum.

[Phys. Rev. Lett. 136, 181001] Published Wed May 06, 2026

We prove positivity of a weighted holographic energy for four-dimensional spacetimes with negative cosmological constant whose conformal boundary at infinity is conformally static and admits either spherical sections, or toroidal sections with compatible spin structure.

[Phys. Rev. Lett. 136, 181401] Published Wed May 06, 2026

Gravitational waves (GWs) from compact binaries are excellent probes of gravity in the strong- and dynamical-field regimes. We report a test of general relativity (GR) with the third GW Transient Catalog (GWTC-3) plus a few O4 events using the recently developed neural post-Einsteinian framework, bo…

[Phys. Rev. Lett. 136, 181402] Published Wed May 06, 2026

The violation of the third law of black hole mechanics in higher dimensional vacuum gravity is numerically demonstrated.

[Phys. Rev. Lett. 136, 171405] Published Fri May 01, 2026