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 the signal rate. We perform a search for such a modulation using data from the SENSEI experiment, targeting MeV-scale dark matter. We achieve nearly an order-of-magnitude improvement in sensitivity over previous direct-detection bounds for dark-matter masses below $\sim 1\mathrm{MeV}$, assuming the standard halo model with a Maxwell-Boltzmann velocity distribution, and restrict the amplitude of a general daily modulation signal to be below $6.8e/\mathrm{g}/\mathrm{d}$.

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 that arise in the long-distance limit of the Einstein-Hilbert action and consists of both the soft graviton mode and the Goldstone mode arising from the spontaneous breaking of supertranslation symmetry. Integrating out the soft graviton mode, we obtain an effective action for purely the Goldstone mode, from which we extract the density matrix and therefore the modular Hamiltonian ${\widehat{K}}_s$ associated to the vacuum state. As a corollary, we explicitly compute the mean and variance of ${\widehat{K}}_s$, finding $⟨\mathrm{\Delta }{\widehat{K}}_s^2⟩=A/{\epsilon }_{\mathrm{UV}}^2$, with ${\epsilon }_{\mathrm{UV}}$ being a length-scale UV cutoff on the celestial sphere.

In the last decades, femtoscopic measurements from heavy-ion collisions have become a popular tool to investigate the strong interactions between hadrons. The key observables measured in such experiments are the two-hadron momentum correlations, which depend on the production mechanism of hadron pairs and the final-state interactions. Given the complexity of ultrarelativistic collision experiments, the source term describing the production mechanism can be modeled phenomenologically only based on numerous assumptions. The commonly employed approach for analyzing femtoscopic data relies on the Koonin-Pratt formula, which relates the measured correlation functions with the relative wave function of an outgoing hadron pair and a source term that is assumed to be universal. Here, we critically examine this universality assumption and show that, for strongly interacting particles such as nucleons, the interpretation of femtoscopic measurements suffers from a potentially large intrinsic uncertainty. We also comment on the ongoing efforts to explore three-body interactions using this experimental technique.

We introduce the $p_T$-differential radial flow $v_0(p_T)$ in the heavy-quark sector. Within an event-by-event Langevin framework, we show that this observable exhibits a strong sensitivity to the heavy quark-bulk interaction. It provides a powerful and novel tool to constrain the transport coefficients of heavy quarks in the quark-gluon plasma and, more generally, to assess the strength of the interaction of a Brownian particle in an expanding bulk medium. The results further indicate that heavy quarks exhibit collective behavior driven by the isotropic expansion of the quark-gluon plasma in heavy-ion collisions and, at low $p_T$, it offers a marked signature of the heavy-quark hadronization mechanism.

The photodisintegration cross sections of the deuteron have been systematically measured over the photon energy range of 2.33–19.65 MeV at the Shanghai Laser Electron Gamma Source. By applying the well-established Baldin sum rule to the newly obtained data, the sum of the electric and magnetic dipole polarizabilities of the deuteron is extracted for the first time based solely on a dense and continuous experimental dataset, yielding ${\alpha }_E+{\beta }_M=0.719\pm 0.009_{\mathrm{stat}}\pm 0.014_{\mathrm{algo}}\pm 0.023_{\mathrm{syst}}{\mathrm{fm}}^3$. With theoretical values of the magnetic polarizability ${\beta }_M$ calculated from the pionless effective field theory, a new value of the electric polarizability is obtained as ${\alpha }_E=0.637\pm 0.009_{\mathrm{stat}}\pm 0.014_{\mathrm{algo}}\pm 0.023_{\mathrm{syst}}\pm 0.004_{\mathrm{theo}}{\mathrm{fm}}^3$, which is in excellent agreement with current theoretical predictions. This result resolves the previous discrepancy between experimental measurements from elastic scattering and theory, providing a high-precision benchmark for nuclear interaction models.

High-harmonic generation (HHG) from liquids offers a potential pathway to attosecond spectroscopy in chemically complex and disordered environments, yet fundamental questions remain open: whether liquid harmonic emission preserves well-defined attosecond synchronization, and whether harmonic emission can involve simultaneous contributions from multiple quantum trajectories with distinct excursion times despite strong disorder and scattering. Here, we address these issues experimentally by establishing the first trajectory-dependent energy-time mapping in liquid HHG. By optimizing the laser focusing geometry, we achieve clear spatial discrimination of short- and long-trajectory contributions, providing direct evidence for the existence of multiple quantum trajectories in liquids. Using a phase-controlled two-color driving field, we independently retrieve the attochirp associated with each trajectory and demonstrate opposite energy-time correlations for short and long trajectories, establishing a trajectory-resolved energy-time mapping in liquid HHG. All observations are well reproduced by semiclassical recollision simulations. These results place liquid HHG on the same conceptual footing as gas- and solid-phase HHG and establish a robust foundation for attosecond-resolved spectroscopy of ultrafast electronic and chemical dynamics in liquid environments.

Ionization is one of the basic physical processes, occurring when charged particles penetrate atomic matter. Here, we predict a novel ionization mechanism, arising in collisions with very dense and compact beams of extreme relativistic electrons, in which a significant fraction of the beam electrons acts coherently as a single “superprojectile.” We compare this mechanism with the tunnel and overbarrier ionization and ionization by individual electrons, demonstrating that it can strongly dominate the ionization process. We also show that this mechanism and the tunnel ionization are very sensitive to the spatiotemporal structure of the beam that can be used for analyzing the beam properties.

Transition-metal perovskite oxides exhibit moderately correlated metallic phases, several of which exhibit a $T^2$ resistivity scaling up to temperatures far exceeding the regime where Fermi-liquid electron-electron scattering is expected to dominate. Some of these materials, such as ${\mathrm{SrMoO}}_3$, also exhibit unexplained ultralow room-temperature resistivity. We demonstrate that in ${\mathrm{SrMoO}}_3$, ${\mathrm{SrWO}}_3$, ${\mathrm{SrTaO}}_3$, ${\mathrm{SrNbO}}_3$, and ${\mathrm{SrVO}}_3$ electron-phonon scattering results in quadratic-scaling resistivity due to the shape of the Fermi surface and the thermal activation of optical phonons. We also reveal that the origin of the low resistivity of ${\mathrm{SrMoO}}_3$ is an overall low electron-phonon coupling strength, and identify ${\mathrm{SrWO}}_3$ and ${\mathrm{SrTaO}}_3$ as other possible low-resistivity oxides. Additionally, we find that the strength of electron-phonon coupling is sensitive to structural distortions, energies of optical phonons, and the treatment of electronic correlations. This suggests design principles for finding other ultrahigh conductivity transition-metal oxides, and has significant implications for theoretical interpretation of direct-current resistivity in transition-metal oxides and beyond.

Recent developments have revealed that symmetries need not form a group, but instead can be noninvertible. Here we use analytical arguments and numerical evidence to illuminate how spontaneous symmetry breaking of a noninvertible symmetry is similar yet distinct from ordinary, invertible, symmetry breaking. We consider one-dimensional chains of group-valued qudits, whose local Hilbert space is spanned by elements of a finite group $G$ (reducing to ordinary qubits when $G={\mathbb{Z}}_2$). We construct Ising-type transverse-field Hamiltonians with $\mathrm{Rep}(G)$ symmetry whose generators multiply according to the tensor product of irreducible representations (irreps) of the group $G$. For non-Abelian $G$, the symmetry is noninvertible. In the symmetry broken phase there is one ground state per irrep on a closed chain. The symmetry breaking can be detected by local order parameters but, unlike the invertible case, different ground states have distinct entanglement patterns. We show that for each irrep of dimension greater than one the corresponding ground state exhibits string order, entanglement spectrum degeneracies, and has gapless edge modes on an open chain—features usually associated with symmetry-protected topological order. Consequently, domain wall excitations behave as one-dimensional non-Abelian anyons with nontrivial internal Hilbert spaces and fusion rules. Our Letter identifies properties of noninvertible symmetry breaking that existing quantum hardware can probe.

Topological singular lines in three-dimensional parameter space—nodal lines and exceptional lines—are fundamental to wave physics and hold promise for advanced photonic control. However, their observation, especially in the optical regime, has been hindered by the challenge of constructing the required parameter space without complex structural engineering. Here, we demonstrate that the scattering matrix of a simple two-dimensional photonic crystal provides such a parameter space through frequency and in-plane momenta, enabling the first observation of chiral exceptional lines in the visible regime. Using high-precision momentum-space Mueller matrix spectroscopy, we map these lines and reveal their key topological features, including self-intersecting Riemann surfaces, phase vortices, and polarization half-vortices, with distinct responses to left- and right-handed circular polarizations. The exceptional lines exhibit characteristic square-root eigenvalue splitting and extend continuously across the frequency-momentum space, demonstrating their topological robustness. This achievement establishes a robust platform for investigating non-Hermitian topological physics at visible frequencies, opening pathways for chiral light-matter interactions, polarization-selective devices, and advanced sensing applications.

High-harmonic generation (HHG) is an extreme form of frequency upconversion that facilitates light-source engineering and ultrafast materials spectroscopy. Here, we broaden the spectroscopic scope of HHG, by demonstrating polarization manipulation of harmonic light in a dielectric, using a two-color field configuration that combines a midinfrared (MIR) driver with a terahertz (THz) perturbation. By varying the relative polarization axes of these fields, the emitted harmonics can be tuned to exhibit either linear or elliptical polarization. Supported by first-principles theory and semiclassical analysis, we show that our approach enables crystal-momentum-resolved dipole-vector spectroscopy across different bands. Crucially, we show that for certain field configurations, harmonic light emission will originate from electron-hole pairs created away from the minimum band gap. Furthermore, crossing MIR and THz polarization at oblique angles generates elliptically polarized harmonics whose microscopic origin is traced to the phase and amplitude imbalances of electron-hole trajectories released during adjacent half-cycles of the MIR field. Our Letter demonstrates new spectroscopy capabilities of HHG, deepens the contemporary microscopic understanding of the process, and paves the way for full polarization control of the harmonic light.

We investigate the dynamics of the Fermi-Pasta-Ulam-Tsingou chain with long-wavelength random initial data. When the energy per particle is small, thermal equilibrium is not reached on a fast timescale, and the system enters prethermalization. The formation of the prethermal state is characterized by the development of a Burgers-type shock and the onset of a turbulentlike spectrum with a time dependent exponent $\zeta (t)$ in the inertial range. We perform a significant step forward by demonstrating that these features are robust under generic long-wavelength random initial conditions. By employing advanced probabilistic techniques inspired by the works of Dudley and Talagrand, we derive a sharp asymptotic expression for the average shock time in the thermodynamic limit. For large $p$, this time scales as $(p\sqrt{\log p}{)}^{-1}$, where $p$ is the number of excited modes, proving that it is an intensive quantity up to a logarithmic correction in the size of the system.

We show that systematic particle rotations in a fluid composed of disk-shaped spinners can spontaneously lead to phase separation. The phenomenon arises out of a homogeneous and hydrostatic stationary state, due to a pressure feedback mechanism that increases local density fluctuations. We show how this mechanism induces phase separation, coined as rotation induced phase separation (RIPS), when the active rotation is not properly counterbalanced by translational friction. A low density phase can coexist with a dense chiral liquid due to the imbalance between pressure and stress transmitted through chiral flows when a significant momentum transfer between rotational and translational motion can be sustained. As a consequence, RIPS is expected to appear as a general nonequilibrium phenomenon in chiral fluids.

In the field of biomolecular condensates and synthetic systems, it is an open question whether liquid droplets can undergo self-sustained oscillations of formation and dissolution. To unravel the minimal physicochemical prerequisite for such droplet oscillations, we present a simple model composed of only two independent chemical components with their diffusive and chemical fluxes governed by nonequilibrium thermodynamics. There is turnover of fuel that maintains a chemical reaction away from equilibrium, leading to active droplets. We find that a single active droplet undergoes a saddle-node bifurcation in the droplet volume upon increasing the fueling strength. Strikingly, the active droplet becomes excitable upon adding a further chemical reaction. For sufficient fueling, the system undergoes self-sustained oscillations.

We investigate universal features of measurement-and-feedback control of quantum chaotic dynamics by examining the quantum Arnold cat map, a paradigmatic model of quantum chaos. Inspired by probabilistic control of classical chaos, our protocol stochastically alternates between intrinsic instability and engineered control operations that steer trajectories toward a target point. Simulation of exact quantum dynamics and a semiclassical truncated Wigner approximation reveal universal properties of the cat map’s control transition. To further characterize this universality, we introduce the inverted harmonic oscillator as an analytically tractable effective model of instability. By integrating numerical simulations, a semiclassical Fokker-Planck description, and a direct spectral analysis of the stochastic quantum channel, we identify quantum signatures absent in classical limits. The close agreement between quantum simulation, truncated Wigner approximation, and inverted oscillator analysis shows that universal features of the transition are set by uncertainty-limited quantum fluctuations and are insensitive to genuine quantum interference.

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 perturbations in curved space are already encoded in the effective field theory, thus bypassing the need for the higher-order calculations that constitute a major hurdle in standard approaches. Concretely, we model the compact body as a spherical shell, whose finite size regulates short-distance divergences in four dimensions and whose tidal responses are described by higher-dimensional operators. As an application, we consider scalar perturbations and derive new results for scalar Love numbers through $\mathcal{O}(G^9)$ for Schwarzschild black holes and for generic compact bodies. Finally, our analysis reveals an intriguing structure of the scalar black-hole Love numbers in terms of the Riemann zeta function, which we conjecture to hold to all orders.

We investigate the interaction-induced resistivity of ultracold fermions in a three-dimensional optical lattice. In situ observations of transport dynamics enable the determination of real and imaginary resistivity. In the strongly interacting metallic regime, we observe a striking saturation of the current-dissipation rate toward a value that is independent of the interaction strength. This phenomenon is quantitatively captured by a dissipation model that uses a renormalized two-body scattering matrix. We further measure the temperature dependence of resistivity in the strongly interacting limit and discuss the predicted asymptotic high-temperature behavior. Our results provide a clear microscopic understanding of bounded resistivity of low-density metals, thus providing a useful benchmark for studies of strongly correlated atomic and electronic systems.