In superconductor-semiconductor hybrid structures, superconductivity and spin polarization are competing effects because magnetic fields break Cooper pairs. They can be combined using thin films and in-plane magnetic fields, an approach that enabled the pursuit of Majorana zero modes, Kitaev chains, and Andreev spin qubits (ASQs), but remains challenging for materials with small in-plane g-factors. Here we show that granular aluminum (grAl), composed of nanometer-scale aluminum grains embedded in an amorphous oxide matrix, can overcome this limitation. By depositing grAl on Ge/SiGe heterostructures, we induce a hard superconducting gap with BCS peaks at 305 $μ$eV and magnetic-field resilience for both the in-plane and out-of-plane directions, allowing Zeeman splitting of Yu-Shiba-Rusinov (YSR) states beyond 50 $μ$eV (12 GHz). Leveraging this robustness, we reveal signatures of hole physics and demonstrate g-tensor tunability.

Active automata learning (AAL) under a Minimally Adequate Teacher (MAT) has been successfully used to infer a regular language through membership and equivalence queries. This language might not be fully characterized: we are then interested in finding any solution in a target class of possibly many regular languages. Some problems such as regular language separation or inductive invariant synthesis in the context of regular model checking (RMC) may indeed admit more than one answer. We therefore introduce IdMAT: a new teacher formalism answering queries with respect to any language in the target class, all at once. Such a teacher tailored towards invariant synthesis might provide incomplete "don't know" answers, but also inductive facts of the form "if w1 is accepted, so is w2". We pair IdMAT with a novel AAL algorithm LIndA that 1. encodes all uncertainties as a unique SAT instance and does not fork, 2. leverages incremental SAT solving and UNSAT core analysis, and 3. handles counterexamples of the simple or inductive type in a frugal manner inspired by the Rivest-Schapire refinement technique. We finally evaluate a prototype implementation in the context of regular language separation and RMC.

Anisotropy in granular materials arises from both the internal fabric and the directionality of the stress state, yet separating these effects experimentally remains challenging. This study develops a first-order linearisation of the incremental stress-strain response that isolates mechanical anisotropy from structural anisotropy using two independent orientation measures. The formulation enables both contributions to be quantified directly from macroscopic laboratory data. The method is applied to hollow-cylinder tests with systematically varied loading directions. Results show that both anisotropy components intensify as the stress state becomes more deviatoric; mechanical anisotropy is consistently stronger; and its relative dominance decreases with increasing deviatoric stress. Comparison with an isotropic hypoplastic model confirms that mechanically induced directional effects are captured even without fabric anisotropy. The framework offers a practical and physically transparent means for quantifying and comparing anisotropy mechanisms in granular materials.

The present study is concerned with a one-dimensional problem in explosive welding that pertains to the collision of lead and steel plates. The metal plates and the surrounding air are represented as separate immiscible phases governed by independent equations of state. A multifluid Godunov-type (finite-volume) computational algorithm, based on the mechanical-equilibrium Euler equations and incorporating pressure relaxation, is used to numerically describe the evolution of the waves resulting from the collision. The position of the interface (contact discontinuity) between immiscible phases is tracked by means of the volume-of-fluid (VOF) method. The numerical model allows one to account for the existence of tensile stresses in metal and registers them as regions of negative pressure. The computed arrival time of the unloading wave at the interface between the plates agrees with the experimental data and with simulation results obtained via different methods.

Biexcitonic states govern singlet fission, triplet-triplet and exciton-exciton annihilation, yet a unified understanding of how these processes compete within a shared electronic manifold remains elusive. We outline a conceptual framework based on fragment-based configuration-interaction that systematically constructs diabatic Hamiltonians spanning the full one-particle (LE, CT) and two-particle (LELE, CTCT, TT, CTX with X = LE, CT, or T) manifolds from monomer-local building blocks, preserving physical interpretability throughout. SymbolicCI provides analytic Hamiltonian matrix elements for efficient large-scale calculations; NOCI-F delivers benchmark-quality couplings. The resulting diabatic Hamiltonians can be coupled to quantum dynamics simulations. Applications to ethylene aggregates and the anthracene crystal reveal CTX configurations as electronic gateways bridging excitonic manifolds, with CT-mediated relaxation pathways competing with conventional annihilation. In H-type aggregates, LECT admixture stabilizes a "bi-excimer" analogous to one-particle excimers. By providing first-principles access to biexciton formation, separation, and transport, we hope to stimulate further exchange between electronic structure and quantum dynamics communities toward a predictive understanding of multiexcitonic photophysics.

Altermegnets are a class of metallic magnets characterized by spin-split electron bands. Like antiferromagnets they lack spontaneous bulk magnetisation. The standard description of the momentum dependent spin splitting of electron bands in altermagnets is based on the spin groups approach, which is valid when relativistic interactions are neglected. The problem of electron bands spin splitting in hexagonal altermagnet CrSb is discussed using magnetic groups formalism that allows to establish the additional spin splitting missed in frame of exchange approximation.

The dispersion curves for the electrons and holes in CsPbI$_3$ in the orthorhombic phase are calculated using the density functional theory (DFT), with the spin-orbit coupling taken into account. The effective masses of the charge carriers are obtained using the parabolic approximation of the dispersion curves in different directions in the $k$-space. It is found that the dispersion curves demonstrate strong nonparabolicity at energies above 0.2 eV for electrons and above 0.1 eV for holes, available for experimental study by the means of optical spectroscopy. We propose a model that describes the dispersion dependences of charge carriers at those energies, where the effective masses of the quasiparticles depend quadratically on the wave vector. An expression is obtained according to the model, which can accurately approximate the dispersion curves for the electron and the hole in all symmetric directions from the center to the boundary of the Brillouin zone.

Despite current security implementations, Internet activity on DoD networks is susceptible to web trackers and commercial data collection, which have the potential to expose information about service members and unit operations. This report documents the outcomes of a study to characterize web tracking occurring on Army CONUS unclassified networks. We derived a dataset from the Cloud-Based Internet Isolation (CBII) platform, encompassing data measured over a two-month period in 2024. This dataset comprised the 1,000 most frequently accessed Internet resources, determined by the number of connection requests on CONUS DoDIN-A during the study period. We then compared all domains and subdomains in the dataset against Ghostery's WhoTracks.me, an open-source database of commercial tracking entities. We found that over 21% of the domains accessed during the study period were Internet trackers. The ACI recommends that the Army implement changes to its enterprise networks to limit commercial Internet-based tracking, as well as policy changes towards the same end. With relatively minor configuration changes, CBII can serve as a more effective mitigation against risks posed by commercially available information.

We present the modeling results of the thermal lightcurve of asteroid (3) Juno at the wavelength of $λ$ = 1.3 mm measured by the Atacama Large Millimeter-submillimeter Array. A thermophysical model together with a radiative transfer model suggest a thermal inertia of 13$\pm$10 [J m$^{-2}$ K$^{-1}$ s$^{-0.5}$], an equivalent emissivity of 0.8$\pm$0.1, a loss tangent of 0.4$\pm$0.3, and an index of refraction 1.8$\pm$0.3. Based on previous laboratory measurements, the modeled index of refraction suggests a regolith porosity of about 45%. However, thermal inertia models using the material parameters of ordinary chondrite indicate a grain size of 10s $μ$m and require a high porosity of $\sim$90% to explain the low thermal inertia. In order to explain such a contradiction, we postulate that some repulsive mechanism might be in effect to reduce the contact of grains and therefore the thermal inertia. The loss tangent of Juno's regolith corrected for the modeled thermal skin depth is in the order of 0.5, much higher than that of the lunar regolith and indicating an electrical skin depth of L = 0.1 - 1.4 mm that is within the thermal skin depth. The shape of the rotational lightcurve of Juno in the mm wavelengths is dominated by its irregular shape, but rotational variations in the thermal and/or dielectric properties cannot be ruled out. Our results demonstrate that mm-wavelength observations of asteroids provide an extra dimension of constraints to the porosity and grain size of asteroid regolith compared to the thermal infrared observations.

Quantum annealing leverages the properties of interacting quantum spin systems to solve computational problems, typically optimisation problems. Current hardware now has capabilities that can be used to solve condensed matter physics problems, too. In this topical review, we provide an overview of quantum annealing aimed at condensed matter physicists, to show the mutual benefits of working together to understand and improve how quantum annealers work, and to use them to advance condensed matter physics.

Many molecules' vibrational frequencies are sensitive to intermolecular electric fields, enabling them to probe the field in complex molecular environments. However, it is often unclear whether the probe is responding to the local electric field or other types of intermolecular interactions, inhibiting interpretation of the frequency and effectiveness as probes. This is especially true of molecules whose vibrational frequencies blueshift instead of the more typical redshift in hydrogen bonding configurations. Here we computationally investigate the causes of redshifting versus blueshifting over a range of vibrational reporters. First, we apply adiabatic energy decomposition analysis to a paradigmatic set of probes, finding that redshifting only occurs when electrostatic interactions are strong enough to overcome the dominant and large blueshifting contribution of Pauli repulsion. Furthermore, we demonstrate that field inhomogeneity can further shift the frequency of many probes substantially to either reinforce or counteract the shift expected from a homogeneous field. We find that redshifting is reinforced by electric field inhomogeneity, otherwise field inhomogeneity further weakens the electrostatic contribution relative to Pauli repulsion, leading to blueshifting. Further calculations indicate that the probe's response to field inhomogeneity can be understood by considering the mass of the atoms involved in the stretching mode and sign of the electric field. In explaining the interplay of different intermolecular interactions and field inhomogeneity for many probes, our results should enable the use and interpretation of spectroscopic probes and their connection to electric fields in more complex systems.

Elemental good metals, including noble metals (Cu, Ag, Au) and several $s$-block elements, do not exhibit superconductivity in bulk at ambient pressure, mainly due to weak electron-phonon coupling that cannot overcome Coulomb repulsion. Quantum confinement in ultra-thin films reshapes the electronic spectrum and the density of states near the Fermi level, producing strong, often non-monotonic, thickness dependencies of the critical temperature in established superconductors. Here, we examine whether confinement alone, or combined with proximity effects, can induce superconductivity in metals that are non-superconducting in bulk form. We review recent theoretical progress and introduce a unified framework based on a confinement-generalized, isotropic one-band Eliashberg theory, where the normal density of states becomes energy dependent and key parameters ($E_F$, $λ$, $μ^$) acquire explicit thickness dependence. By numerically solving the Eliashberg equations using ab initio or experimentally determined electron-phonon spectral functions $α^2F(Ω)$ and Coulomb pseudopotentials $μ^$, and without adjustable parameters, we compute the critical temperature $T_c$ as a function of film thickness for representative noble, alkali, and alkaline-earth metals. The results predict that superconductivity emerges only in selected cases and within extremely narrow thickness windows, typically at sub-nanometer scales ($L \sim 0.4-0.6$ nm), indicating strong fine-tuning requirements for confinement-induced superconductivity in good metals. We also consider layered superconductor/normal-metal systems where confinement and proximity effects coexist. In these heterostructures, a substantial enhancement of the critical temperature is predicted, even when the constituent materials are non-superconducting or weak superconductors in bulk form.

Intelligent text entry (ITE) methods, such as word suggestions, are widely used in mobile typing, yet improving ITE systems is challenging because the cognitive mechanisms behind suggestion use remain poorly understood, and evaluating new systems often requires long-term user studies to account for behavioral adaptation. We present WSTypist, a reinforcement learning-based model that simulates how typists integrate word suggestions into typing. We extend recent hierarchical control models of typing, by identifying and implementing important cognitive mechanisms that underlie the high-level decision-making for integrating word suggestions into manual typing: considering orthographic processes, assessing efficiency gains, and including personal preference on AI support. Our evaluations show that WSTypist simulates diverse human-like suggestion-use strategies, reproduces individual differences, and generalizes across different systems. Importantly, we demonstrate on four design cases how a computational rationality model can be used to inform what-if analyses during the design process, by simulating how users might adapt to changes in the UI or in the algorithmic support, reducing the need for long-term user studies.

Measurement plays a crucial role in a quantum system beyond just learning about the system state: it changes the post-measurement state and hence influences the subsequent time evolution; further, measurement can even create entanglement in the post-measurement conditional state. In this work, we study how careful choice of parameters for a typical measurement process on cold atoms systems -- phase contrast imaging -- has a strong impact on both what the experimentalist observes but also on the backaction the measurement has on the system, including the creation and diffusion of quasiparticles emerging from the quantum many-body dynamics. We focus on the case of a Bose-Einstein-condensate array, in the low-temperature and low-momentum limit. Our theoretical investigation reveals regimes where the imaging light probes either the bare particle or quasiparticle dynamics. Moreover, we find a path to selectively measuring quasiparticle modes directly, as well as controlling over the measurement-induced creation and diffusion of quasiparticles into different momentum states. This lays a foundation for understanding the effects of both experimental approaches for probing many-body systems, but also more speculative directions such as observable consequences of `spontaneous collapse' predictions from novel models of quantum gravity on aspects of the Standard Model.

Heavy-to-heavy semileptonic decays, particularly the bottom-to-charm quark transitions, are essential for testing the Standard Model (SM) and extracting the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements. These decays have been extensively studied using various theoretical approaches. In this work, we investigate the semileptonic decay $Ξ_b^0 \rightarrow Ξ_c^+\ell\barν_{\ell}$ (where $\ell = e$, $τ$) using a phenomenological quark model. We compute the ground-state masses of the initial and final baryons to get the wave function, which is then used to calculate the form factors, including corrections up to order $1/m_Q$ within the framework of Heavy Quark Effective Theory (HQET). The obtained form factors are implemented in the helicity formalism to evaluate the differential decay rates, total decay width and branching ratio. We compare our results for the form factors at both the maximum and minimum recoil points with previous theoretical studies, finding good agreement. We observe that the form factors depend on the transferred momentum $q^2$ and their magnitude gradually increases with increasing $q^2$. The dominant form factors are $f_1$ and $g_1$, and they also exhibit similar $q^2$ dependencies. Additionally, we calculate the lepton flavour universality (LFU) ratio $R(Ξ_c) \approx 0.3$, which is in agreement with existing theoretical predictions.

We investigate the direct and inverse Mpemba effects within the framework of the time-delayed Newton's law of cooling by introducing and analyzing the Descartes protocol, a three-reservoir thermal scheme in which each sample undergoes a single-step quench at different times. This protocol enables a transparent separation of the roles of the delay time $τ$, the waiting time $t_{\text{w}}$, and the normalized warm temperature $ω$, thus providing a flexible setting to characterize anomalous thermal relaxation. For instantaneous quenches, exact conditions for the existence of the Mpemba effect are obtained as bounds on $ω$ for given $τ$ and $t_{\text{w}}$. Within those bounds, the effect becomes maximal at a specific value $ω=\widetildeω(t_{\text{w}})$, and its magnitude is quantified by the extremal value of the temperature-difference function at this optimum. Accurate and compact approximations for both $\widetildeω(t_{\text{w}})$ and the maximal magnitude $\text{Mp}(t_{\text{w}})$ are derived, showing in particular that the absolute maximum at fixed $τ$ is reached for $t_{\text{w}}=τ$. A comparison with a previously studied two-reservoir protocol reveals that, despite its additional control parameter, the Descartes protocol yields a smaller maximal magnitude of the effect. The analysis is extended to finite-rate quenches, where strict equality of bath conditions prevents a genuine Mpemba effect, although an approximate one survives when the bath time scale is sufficiently short. The developed framework offers a unified and analytically tractable approach that can be readily applied to other multi-step thermal protocols.

A monitoring edge-geodetic set (or meg-set for short) of a graph is a set of vertices $M$ such that if any edge is removed, then the distance between some two vertices of $M$ increases. This notion was introduced by Foucaud et al. in 2023 as a way to monitor networks for communication failures. As computing a minimum meg-set is hard in general, recent works aimed to find polynomial-time algorithms to compute minimum meg-sets when the input belongs to a restricted class of graphs. Most of these results are based on the property of some classes of graphs to admit a unique minimal meg-set, which is then easy to compute. In this work, we prove that chordal graphs also admit a unique minimal meg-set, answering a standing open question of Foucaud et al.

Controversy about the significance of underdetermination of theories persists in the philosophy and conduct of science. The issue has practical import when research is used to inform decision making, because scientific uncertainty yields inductive risk. Seeking to enhance communication between philosophers and researchers who study public policy, this paper describes econometric analysis of partial identification and its use in welfare-economic policy analysis. Study of partial identification finds underdetermination and inductive risk to be highly consequential for credible prediction of important societal outcomes and, hence, for credible public decision making. It provides mathematical tools to characterize a broad class of scientific uncertainties that arise when available data and well-supported assumptions are combined to predict population outcomes. Combining study of partial identification with criteria for reasonable decision making under uncertainty yields coherent approaches to make policy choices without accepting one among multiple empirically underdetermined theories. The paper argues that study of partial identification warrants attention in philosophical discourse on underdetermination and inductive risk.

Conflict-Free Replicated Data Types (CRDTs) are used in a range of fields for their coordination-free replication with strong eventual consistency. By prioritising availability over consistency under partition, peers accumulate events in different orders, and rely on an associative, commutative and idempotent merge function to present a materialised view of the CRDT. Under some circumstances, the state of the materialised view over time can appear to ''roll back'' previously applied events. When the materialised view is used to manage group permissions such as ones found in instant messaging applications, this can lead to surprising behaviour. Rollbacks can occur when there are multiple concurrent events, such as in the Duelling Admins problem where two equally permissioned admins concurrently revoke each other's permissions. Who wins? Different solutions and their trade-offs are examined. A Byzantine admin can exploit concurrency to influence the duel, whereby we argue that an external arbiter is required to order concurrent events. Our ERA proposal arbitrates asynchronously in batches via optional ''epoch events'', preserving availability. This introduces a bounded total order within epochs, and the resulting ''finality'' improves on the level of consistency CRDTs can provide.

We present a thermodynamically consistent model for chemically driven running drops on a solid substrate with reversible substrate adsorption of a wettability-changing chemical species. We consider drops confined to a vertical gap, thereby allowing us to first obtain a gradient dynamics description of the closed system, corresponding to a set of coupled dynamical equations for the drop profile and the chemical concentration profiles of species on the substrate and in both fluids (drop, ambient medium). Chemostatting the species in the drop and the ambient medium, we then derive a reduced model for the dynamics of the drop and the adsorbate on the substrate. When the externally imposed chemical potentials are distinct, the system is driven away from thermodynamic equilibrium, allowing for sustained drop self-propulsion across the substrate due to a wettability contrast maintained by chemical reactions. We numerically study the resulting running drops and show how they emerge from drift-pitchfork bifurcations.

A number of candidate repeating partial tidal disruption events (rpTDEs) have been reported in recent years. If these events are confirmed, the high fraction of observed rpTDEs among all tidal disruption events (TDEs) is in tension with prediction of the loss cone channel. We further point out an inequality $M_\bullet \lesssim 4\times 10^6 M_\odot (T_{\rm obt}/10\ {\rm yr})^{4/9}$ that must be satisfied for rpTDEs of solar type stars in the loss cone channel, where $M_\bullet$ is the central supermassive black hole (SMBH) mass and $T_{\rm obt}$ is the orbital period of the star. However the majority of reported rpTDE candidates potentially violate this inequality, indicating an alternative formation channel. In the commonly invoked Hills mechanism, the captured stars produced by tidal disruption of near-contact binaries can evade this inequality and may be the dominant source of rpTDEs. If the same process operates in the Galactic Center, there should exist a population of hypervelocity stars (HVSs) ejected with velocities as high as $3.6\times 10^3 (M_\bullet/10^6 M_\odot)^{1/6}\ {\rm km\ s}^{-1}$, which however have not been detected. A complete search for HVSs in the Milky Way will be critical for testing this prediction.

We initiate a systematic study on how to extract planar integrands of (supersymmetric) scattering amplitudes with $L$ loops and $n$ legs in Aharony-Bergman-Jafferis-Maldacena (ABJM) theory from the recently proposed (bosonic) generating function for squared amplitudes with $N:=n{+}L$ dual points; the latter enjoys a hidden permutation symmetry $S_N$ and is given by a linear combination of weight-$3$ planar $f$-graphs that can be recast as bipartite graphs, which manifest important properties of ABJM amplitudes. We provide evidence that it contains sufficient information to reconstruct individual amplitudes, despite the absence of squared amplitudes at odd loops. The extraction of the four-point amplitude is already non-trivial and closely parallels the extraction of five-point amplitudes in ${\cal N}=4$ super Yang-Mills (SYM) from weight-$4$ $f$-graphs: we comment on this similarity and provide new results for $n=4$ ABJM loop integrand up to $L=6$. For higher multiplicities, based on Yangian invariants (including BCFW building blocks for tree amplitudes) and an appropriate basis of planar dual conformal invariant(DCI) integrands, we disentangle six-point integrands up to two loops and eight-point tree amplitude from the squared amplitudes. Our results suggest that ABJM amplitudes of arbitrary multiplicity and loop order can be reconstructed from squared amplitudes, closely paralleling the role of $f$-graphs in $\mathcal{N}=4$ SYM.

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

In the first half of 2025, coding agents have emerged as a category of development tools that have very quickly transitioned to the practice. Unlike ''traditional'' code completion LLMs such as Copilot, agents like Cursor, Claude Code, or Codex operate with high degrees of autonomy, up to generating complete pull requests starting from a developer-provided task description. This new mode of operation is poised to change the landscape in an even larger way than code completion LLMs did, making the need to study their impact critical. Also, unlike traditional LLMs, coding agents tend to leave more explicit traces in software engineering artifacts, such as co-authoring commits or pull requests. We leverage these traces to present the first large-scale study (128,018 projects) of the adoption of coding agents on GitHub, finding an estimated adoption rate of 22.20%--28.66%, which is very high for a technology only a few months old--and increasing. We carry out an in-depth study of the adopters we identified, finding that adoption is broad: it spans the entire spectrum of project maturity; it includes established organizations; and it concerns diverse programming languages or project topics. At the commit level, we find that commits assisted by coding agents are larger than commits only authored by human developers, and have a large proportion of features and bug fixes. These findings highlight the need for further investigation into the practical use of coding agents.

We investigate the existence of black bounce solutions in $2+1$ dimensions within the framework of $f(R)$ gravity. We analyze whether black bounce geometries originally obtained in general relativity can be consistently generalized to $f(R)$ theories and identify the matter sources capable of supporting such solutions. We also construct a new class of solutions by imposing a vanishing curvature scalar. In the matter sector, we consider models involving a coupling between a scalar field and nonlinear electrodynamics, while in the gravitational sector we analyze both the Starobinsky model and more general forms of $f(R)$. We further examine the viability conditions of the $f(R)$ models that give rise to these spacetimes, including the behavior of the scalaron mass. Finally, we study the associated energy conditions, in order to assess the degree of exoticity of the matter content required to sustain these black bounce solutions and how the $f(R)$ theory modifies the energy conditions.

We provide a framework which generalizes algebraic models of a homotopy theory of spaces to the genuine equivariant case for a discrete group. We explain how this applies to commutative differential graded algebra (cdga) models and complete differential graded Lie algebra models for rational spaces. We compare the cdga model to other model categories in the literature.

We study holographic defect conformal field theories which are dual to probe branes with bottom-up methods. First we determine the embedding of codimension-1 interface branes in AdS space. Then we compute defect one and two-point functions of heavy scalar operators at strong coupling. We use geodesic approximations to compute reflected two-point functions in two ways, as well as ambient and defect-channel two-point functions. In appropriate limits, our results agree with the operator product expansion (OPE) and the boundary operator expansion (BOE).

A large-scale molecular dynamics (MD) simulation of acoustic cavitation in a simple liquid was performed using the supercomputer Fugaku. The system, consisting of approximately 100 billion atoms, was subjected to ultrasonic irradiation. Direct observation of multi-bubble dynamics has been challenging in both experimental measurements and conventional numerical fluid mechanics simulations. Moreover, previous MD simulations involving only hundreds of millions of atoms were unable to generate multiple bubbles within a system. Our results reveal that cavitation bubbles nucleate and grow near the ultrasonic horn, forming a large bubble cluster that periodically splits into multiple small clusters and subsequently merges again. This cycle is synchronized with the oscillation period of the horn. Pressure and temperature inside the bubbles exhibit sharp increases during cluster fragmentation, and their oscillation amplitudes vary on a timescale longer than the driving period of the horn, indicating the presence of subharmonic behavior consistent with experimental observations. Despite bubble formation, the effect on the acoustic properties of the sound wave was almost negligible, indicating that cavitation near the horn surface has limited influence on bulk acoustic properties. These findings provide new insights into the molecular-scale mechanisms of cavitation and offer guidance for optimizing ultrasonic systems in chemical and biomedical applications. Future work will focus on quantifying long-period oscillations, analyzing attenuation effects, and extending simulations to complex fluids.

Correlated materials with competing spin-orbit and crystal-field interactions can host composite spin-orbital magnons that are highly susceptible to structural and electronic perturbations, enabling the control of magnetic dynamics beyond spin-only physics. Using Raman spectroscopy on Ca$_2$RuO$_4$, we show that the partial substitution of Ru with Mn reconstructs the magnon spectrum and reveals one-magnon modes that are hidden in the undoped state. We demonstrate that the transition-metal substitution activates otherwise symmetry-forbidden magnon modes through mirror-symmetry breaking of the underlying spin-orbital configuration. This effect can be theoretically explained by the local structural distortions induced in the RuO$_6$ octahedra near the dopant, that enable the observation of mixed-parity one-magnon modes. These excitations display a distinctive polarization dependence, with a lowering from fourfold to twofold rotational symmetry arising from the mixed-parity character of the coupled magnons and interference between resonant and nonresonant scattering channels. Our results show that spin-orbit-lattice entanglement provides a route to tailoring collective magnetic excitations and their polarization response in spin-orbit-coupled correlated systems.

The binary black hole signal GW250114, the clearest gravitational wave detected to date, offers a unique opportunity to test general relativity in the relativistic strong-gravity regime. How well does GW250114 agree with Einstein's predictions in the plunge-merger-ringdown stage? To address this point, we constrain deviations from general relativity across the plunge-merger-ringdown stage of spin-precessing binaries with a parametrized waveform model within the effective-one-body formalism. We find that deviations from the peak gravitational-wave amplitude and instantaneous frequency of the $(\ell, |m|)=(2,2)$ mode are constrained to about $10\%$ and $4\%$, respectively, at $90\%$ credible level. These constraints are, respectively, two and four times more stringent than those obtained by analyzing GW150914. We also constrain, for the first time, the instantaneous frequency of the $(\ell, |m|)=(4,4)$ mode at merger to about $6\%$, and the time at which the gravitational-wave amplitude peaks to about $5~\mathrm{ms}$. These results are the most precise tests of general relativity in the nonlinear regime to date, and can be employed to constrain extensions of Einsten's theory.