Papers

Generalized Toric Polygons (GTPs) extend the geometric realization of $5d$ superconformal field theories beyond toric Calabi-Yau 3-folds to general $(p,q)$ 5-brane webs ending on 7-branes. We take significant steps towards the generalization of brane tilings for GTPs, or equivalently, the corresponding quiver theories. We focus on GTPs connected to ordinary toric diagrams by polytope mutations. Parallel 5-brane legs of a $(p,q)$ web define $\mathcal{N}=2$ fractional branes bounded by the corresponding parallel zig-zag paths in the brane tiling obtained by treating the GTP as an ordinary toric diagram. We propose that terminating multiple 5-branes on a common 7-brane, the defining feature of GTPs, translates into bringing these zig-zag paths together, thereby shrinking the corresponding $\mathcal{N}=2$ fractional branes to zero size in a process we call $\mathcal{N}=2$ strip condensation. We show that strip condensation follows from mirror symmetry when the coefficients in the Newton polynomial are tuned to the GTP point. We further support this proposal through several non-trivial consistency checks. In particular, it correctly reproduces the expected number of gauge groups, given equivalently by that of the mutation-related toric diagram or by the number of $T$-cones in a tessellation of the GTP. We verify this for all examples previously considered in the literature, as well as for a new infinite family of GTPs with arbitrarily large $T$-cones. Strip condensation drives the corresponding gauge groups to infinite coupling. Confinement then yields quivers that coincide with those of the mutation-related toric diagrams up to vector pairs and adjoint fields, suggesting that GTP quivers are related to those of the corresponding toric diagrams by relevant deformations, extending to GTPs the known correspondence between polytope mutations and relevant deformations.

Recent JWST/NIRSpec observations have shown that Na I D absorption tracing neutral gas outflows is widespread in massive galaxies at Cosmic Noon ($z\sim2$-$3$), but their prevalence at higher redshift remains largely unexplored. Here we investigate whether similar outflows are already in place during the first 2 Gyr of cosmic history ($z>3$), using a sample of 811 galaxies at $3<z<7$ from the public DAWN JWST Archive and the Mirage or Miracle survey, with secure spectroscopic redshifts and continuum SNR$>5$ in their JWST/NIRSpec PRISM low-resolution spectra ($R\sim100$). We derived physical properties and star formation histories via Prospector SED fitting and isolated the Na I D feature in each spectrum by subtracting the best-fit stellar continuum. We detect an excess of Na I D absorption in 20 galaxies, almost all at $3<z<5$ with stellar mass $>10^{10} M_\odot$, an overall detection fraction of $\sim2.5\%$. The detection fraction rises steeply with stellar mass and quiescence, reaching $\sim11\%$ among the most massive galaxies and $\sim43\%$ among massive quenched systems. The Na I D equivalent widths are large, spanning 4 to 16 Angstrom, and are highest in dusty star-forming galaxies. In previous medium-resolution observations, EWs above 5 Angstrom were mostly found in outflowing gas; we thus interpret our detections as mostly tracing neutral outflows, despite the lack of kinematic information at PRISM resolution. A stacking analysis confirms these trends and provides average Na I D EWs for different subsamples. Under conservative assumptions, we estimate mass outflow rates of 4 to 12 $M_\odot$ yr$^{-1}$, exceeding the current star formation rate for about 30% of the detected galaxies. We conclude that neutral outflows are likely already present and important in massive galaxies during the first 2 Gyr of cosmic history.

We show that the self-correcting memory in 3d Wegner gauge theory is stable to arbitrary small enough perturbations of the Hamiltonian. Our proof relies on a new method we dub “gauge averaging”, which gives conditions under which explicitly broken gauge symmetries are effectively restored by fluctuations. These conditions show that the self-correcting memory phase is fluctuation stabilized, with its robustness to perturbations increasing with increasing temperature, up to some $T_c > 0$.

We present a systematic study of the currently available ALMA millimeter polarimetric sample of gamma-ray burst (GRB) afterglows. Our sample comprises 24 observations (20 new) of 11 long-duration GRBs spanning $\approx0.1$-87 days after the burst. We detect significant linear polarization in 8 observations across 6 events, with polarization degrees ranging from $\Pi_L\approx0.6\%$ to $2.4\%$. For the remaining observations, we place deep upper limits (median $\Pi_L\lesssim1\%$). Multi-epoch observations reveal diverse polarization evolution. GRB 190114C yields the best-sampled $\Pi_L$ for a radio afterglow to date, with early evolution favoring patchy magnetic fields in the reverse shock (RS) and later polarization broadly consistent with forward-shock (FS) models. GRB 220921A exhibits a rapid rise in polarization from $\Pi_L\lesssim0.4\%$ to $2.4\%$ over 1.9-6.8 days, inconsistent with toroidal RS magnetic-field models but broadly consistent with several FS random-field models. GRB 221009A yields the highest-significance polarization detections in the sample ($\Pi_L\approx1.4$-$1.6\%$), yet neither existing FS nor RS polarization models reproduce both the observed polarization evolution and the viewing geometry inferred from broadband afterglow modeling, with the exception of patchy fields in the RS. Deep upper limits for GRB 171205A rule out RS toroidal-field models for the published off-axis geometry, while a strong, single-epoch detection of GRB 190829A, if RS-dominated, requires a nearly on-axis geometry for toroidal-field configurations. Interpreting the observations within a patchy-field framework implies magnetic-field coherence scales of order $\theta_B\sim10^{-3}$-$10^{-2}$ rad. These observations demonstrate the diagnostic power of radio/mm polarimetry for probing the magnetic-field structure, emission region, and viewing geometry of relativistic GRB jets.

At asymptotic limits of moduli spaces of quantum gravity vacua, we argue that the masses of the lightest particle towers are eigenfunctions of the moduli-space Laplacian. The associated eigenvalues are quantized by the Emergent String Conjecture and determine the exponential decay rates of axionic directions in these limits. We also connect the quantization of Laplacian eigenvalues to the spectrum of instantons for the theory. We support our claims with diverse examples that preserve between 4 and 32 supercharges.

Estimation of work at the quantum scale remains a central challenge in quantum thermodynamics. Canonical approaches have a fundamental drawback: they assume classical control of the quantum system, as implicit in a time-dependent Hamiltonian. Yet the energetic cost of implementing this control is omitted and can exceed the system's energy scale by orders of magnitude, calling into question the operational significance of work values. We address this by autonomizing the controlled energy transfer, embedding the driven dynamics into an energy-conserving evolution on a larger quantum system. Work is then unambiguously identified with the energy transferred between the two systems, singling out a unique observable on the driven system: the work operator. We show that the quantum work operator evades a no-go theorem by deriving a quantum fluctuation theorem that recovers the Jarzynski equality in classical scenarios. We incorporate imperfect control and quantify corrections to work statistics. Extending the framework to open quantum systems, we obtain an operatorial first law in which work, heat, and internal-energy changes are represented by distinct operators on the reduced system. Together, these results settle the long-standing debate over whether work is a quantum observable: it is, once the controlling system is included in the description rather than treated as external.

Fast radio burst (FRB) dispersion measures (DMs) are powerful tracers of the low density universe, but interpretation is made difficult by the integrated nature of DM. In this paper, we analyze the new ENGAWA cosmological zoom-in simulation suite to constrain the DM contribution from the Milky Way (MW) halo. The ENGAWA simulations consist of four Milky Way-like galaxies with enhanced resolution in the circumgalactic medium, making them an excellent tool to probe the properties of the gaseous halo. The median all-sky DM from the galactic halos in ENGAWA span 19-39 pc cm$^{-3}$, varying even at fixed feedback strength, halo mass, and $f_\mathrm{CGM}$. These simulations show that, with enhanced circumgalactic resolution, the mean halo DM values are in general lower with more anisotropy across the sky than previous models, reaching < 10 pc cm$^{-3}$ towards the poles. Furthermore, by varying the solar position within the simulated galaxies, we have obtained an estimate of the uncertainty in DM given our location in the MW. We provide a Python package with MW halo DM values from the simulation accessible via API functions of Galactic longitude and latitude. These new, simulation-based MW halo DM estimates will provide a critical baseline for interpretations of future FRB observations and our understanding of the global gas distribution in the Universe.

Parity symmetry, with an extended gauge group $SU(3)_c \times SU(2)_L \times SU(2)_R \times U(1)_X$, can solve the strong CP problem. In particular, the model where $SU(2)_R\times U(1)_X$ is broken by the Parity partner of the Standard Model Higgs solves the strong CP problem without the necessity of introducing extra symmetry. We discuss the possibility of accidentally stable dark matter in this framework and show that $SU(2)_L \times SU(2)_R$ bi-triplet fermions can be stable over cosmological timescales. We compute the relic abundance of the bi-triplet dark matter and derive constraints on the parameter space from collider, direct-detection, and indirect-detection experiments. The $SU(2)_R\times U(1)_X$ symmetry breaking scale is required to be below 150 TeV, and most of the parameter space can be probed by near-future indirect-detection experiments.

A binary undergoing dynamically unstable mass transfer could rapidly shrink its orbit and lead to a merger, with the whole process often observable in human timescales. We construct a semi-analytical light curve model of binary systems composed of a star and a compact object accretor, that would display long-rising accretion-powered emission prior to a final merger-driven explosion. We apply the model to the precursors of interacting supernovae (SNe) that display long-rising light curves of years, SN 2023zkd, 2023fyq and 2021qqp, demonstrating the model's capability of inferring the mass-transfer history and constraining the progenitor binary system. The model and the parameter inference framework, encapsulated in a publicly-released script, can be applied to existing long-rising precursors of SNe as well as many SN precursors to be discovered by surveys like those from the Vera C. Rubin Observatory.

Lattice dynamics are widely invoked in the design of solid electrolytes, yet phonon information is commonly compressed into a band center or another scalar softness measure. Here we test whether the complete lithium-projected phonon density of states (Li-PDOS) provides a reproducible descriptor of experimental room-temperature ionic conductivity. MatterSim forces and Phonopy were used to generate harmonic total and Li-projected spectra for crystallographically resolved entries in the OBELiX dataset. A composition and structure audit defined a primary cohort of 260 materials (212 train and 48 test), a strict cohort of 241, and an exact-composition cohort of 168. Across 20 independently generated phonon-calculation database comparisons, the mean Wasserstein-1 distance was 0.542 THz for total DOS and 0.731 THz for Li-PDOS, revealing broad agreement but systematic, projection-dependent softening. Higher conductivity was associated with redistribution of normalized Li spectral weight toward low frequencies: in the untouched test set, the Li fractions below 2 and 5 THz had Spearman coefficients of 0.333 and 0.374, while the 5$\%$ cumulative-frequency quantile had a coefficient of $-0.393$. A Wasserstein kernel on the full Li-PDOS achieved held-out $R^2=0.444$, compared with 0.012 for total DOS and 0.181 for a static composition–structure kernel. The Li model remained stable in the strict ($R^2=0.462$) and exact ($R^2=0.451$) cohorts. Family adjustment attenuated scalar associations, and Li-versus-total whole-spectrum dependence was cohort sensitive. The results therefore support mobile-ion-resolved spectral distributions as useful comparative screening descriptors, not as a universal causal softness law.

Higgsino dark matter (DM) is considered one of the most well-motivated and minimal DM scenarios arising from supersymmetric extensions of the Standard Model. Motivated by the requirement of electroweak naturalness, Higgsinos are expected to be relatively light, with masses close to the weak scale. While a pure Higgsino state typically evades current direct detection limits, next-to-leading (NLO) order radiative corrections may bring it within the sensitivity of upcoming experiments. On the contrary, a more important consequence, observed specifically near the kinematic threshold for the production of two particles, is that the NLO corrections lower the DM-nucleon cross section below the neutrino floor. We explicitly examine the cancellation mechanism responsible for suppressed Higgsino-nucleon scattering and identify regions of MSSM parameter space where spin-independent cross-sections may vanish.

Sample-based quantum diagonalization (SQD), an extension of quantum selected configuration interaction (QSCI), is a promising hybrid quantum-classical paradigm for molecular ground-state energies. By replacing variational optimization with quantum sampling, QSCI avoids barren plateaus and directly reconstructs correlated wavefunctions. However, existing configuration recovery mainly enforces symmetry constraints without targeting the most physically relevant configurations, often yielding oversized subspaces and costly classical diagonalization. We introduce QSCI-RBM, a compact subspace generation protocol based on Restricted Boltzmann Machines (RBMs), and integrate it within Density Matrix Embedding Theory (DMET). The RBM learns the distribution of dominant determinants from hardware samples, generating high-probability configurations. Sampling was performed on IBM Heron R1 (ibm\_torino) for CH$_5$NO, R2 (ibm\_fez) for C$_2$H$_4$, and R3 (ibm\_boston) for the larger H$_2$O benchmark and the protein-ligand system. After validating on these benchmarks of increasing active-space size, we simulate the inhibitor Carmofur bound to the SARS-CoV-2 main protease (M\textsuperscript{pro}), fragmented into ten DMET impurities. Both DMET-QSCI-RBM and a DMET-SQD baseline reach chemical-potential self-consistency within four $\mu$-iterations. At the converged chemical potential, DMET-QSCI-RBM lies within $0.05\,\mathrm{mHa}$ of DMET-FCI while accessing on average only $0.22\%$ of the symmetry-preserving configuration space, versus $0.55\,\mathrm{mHa}$ at $33.0\%$ for DMET-SQD, leading to a $\sim$153-fold subspace reduction. RBM-assisted expansion thus yields far more compact hardware-derived determinant spaces at equal or better accuracy, reducing classical overhead for scalable quantum embedding of biological systems on real hardware.

A sixth-order gravity, which involves not only two leading terms, $\gamma_1 R\Box R$ and $\gamma_2 R_{\mu\nu} \Box R^{\mu\nu}$, but also quadratic curvature terms along with cubic curvature ones, will be investigated in this paper to see if it admits an exact stable de Sitter solution. First, we will derive sixth-order differential field equations of this gravity under the homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker background spacetime, using the effective method based on the Euler-Lagrange equations. Then, we will analytically solve these field equations to figure out an exact de Sitter solution, which turns out to be equivalent to a fixed point of the corresponding dynamical system of the studied gravity. Interestingly, two coefficients, $\gamma_1$ and $\gamma_2$, do not contribute to the value of the obtained de Sitter solution. However, they affect on the stability of the de Sitter solution. In particular, if these two coefficients obey the following inequality, $3\gamma_1+\gamma_2 <0$, then the de Sitter solution will always be unstable. Furthermore, numerical calculations will be performed to verify that the de Sitter fixed point is indeed a repeller of the dynamical system once this inequality is satisfied. All these results indicate that the sixth-order gravity is more suitable for an inflationary phase of early universe. To be complete, two special limits of the studied gravity model, in which field equations are reduced to second-order and fourth-order, respectively, will be investigated. As expected, only the second-order limit can always give raise a stable de Sitter solution, compatible with an accelerated expansion of late-time universe.

We examine whether scalar eikonal quasinormal-mode data determine black-hole thermodynamics. For static, spherically symmetric, asymptotically flat, nonextremal geometries, we prove that the formal fixed-overtone expansion of a neutral, minimally coupled, massless scalar through order $L^{-N}$ depends only on the $(2N+2)$ jet of the lapse at the unstable photon sphere. For every finite $N$, real-analytic deformations can preserve this jet and the asymptotic Reissner–Nordström coefficients while changing the surface gravity and Hawking temperature. We also construct a nonanalytic $C^\infty$ deformation that is flat at the photon sphere. This deformation preserves the complete formal eikonal series to every algebraic order but changes the horizon position, temperature, and Einstein area entropy. A nonempty charged subfamily satisfies the weak energy condition as an effective Einstein source. Together, these four results establish the new finite-jet and all-orders thermodynamic obstruction. To separate geometric information from action-dependent information, we incorporate a previously established Reissner–Nordström–MOG comparison. The mapped backgrounds have identical normalized metrics, neutral-scalar boundary-value problems, exact scalar spectra, and Hawking temperatures, yet their Wald entropies differ because their curvature couplings differ. The resulting hierarchy shows that local photon-sphere data do not determine horizon thermodynamics and that even exact action-blind scalar data do not determine gravitational entropy. Agreement of the formal eikonal expansions for the deformed metrics does not imply exact finite-$\ell$ isospectrality. Global differences may appear beyond every algebraic order. Thermodynamic reconstruction from eikonal ringdown is therefore conditional on assumptions about the global metric and the gravitational action.

Quantum Fisher Information (QFI) is a powerful spectroscopic tool to witness many-body quantum entanglement in solid state materials, but it is not always obvious how to relate it to other characteristics of condensed matter systems. In this study we elaborate on the meaning and interpretation of QFI in condensed matter by examining simple theoretical spin systems. We use finite sized spin systems to illustrate that QFI quantifies the momentum- dependent degree of quantum entanglement (that is the entanglement depth at a given wave vector) within a wave function. We subsequently use semiclassical frustrated spin models to show that, in the context of linear spin wave theory (LSWT), QFI quantifies the momentum-dependent degree of magnon squeezing in the ground state. In antiferromagnets with a zero-energy Goldstone mode, LSWT breaks down and QFI (and entanglement depth) diverges at the magnetic ordering wave vector. We also show examples of emergent quantum phases in frustrated spin systems that do not appear in classical phase diagrams. When these emergent phases are approached, QFI diverges across multiple wave vectors in momentum space. Taken together, QFI is not only helpful as a lower bound for entanglement depth, but serves as a momentum-resolved probe of entanglement that offers a novel perspective on quantum critical phenomena.

We study primordial black-hole (PBH) formation in a single-field model which passes from slow roll, through a transient ultra-slow-roll phase, into kination. Nonlinear numerical-relativity simulations are used to follow localised, initially sub-Hubble field fluctuations across the non-attractor transition, to determine the resulting super-Hubble curvature profiles, and subsequently to evolve their re-entry during kination. Within the set of initial configurations explored here, we find three qualitatively distinct outcomes, namely a patch which remains trapped in inflation, a positive-curvature overdensity, and a negative-curvature void bounded by an overdense shell. Each may form a PBH, although by a different physical mechanism. For one selected profile in each of the overdense and void channels, we measure collapse thresholds and compare them with thresholds for sinc profiles. The comparison shows that neither the central curvature nor the peak linear compaction alone provides a profile- or channel-independent collapse criterion. PBH abundances in non-attractor models must therefore be formulated in terms of the distribution of complete profiles, with the trapped, overdense, and void channels treated separately.

Classical low-density parity-check (cLDPC) codes defined on expander graphs are a fundamental ingredient in the construction of good quantum LDPC codes, a recent milestone in quantum error correction. They also define interesting statistical mechanics models in their own right, as they include examples of spin glass order without quenched randomness or frustration. We investigate this via a case study of a cLDPC code on a locally tree-like expander graph. Recursive techniques on trees, made possible by the locally tree-like property, probe a menagerie of stable, incongruent valleys induced by imposing different boundary conditions at low temperature. Analysis of stable and unstable fixed points within the cavity method, complemented by a numerical study of the valleys on closed finite graphs, reveals the inequivalence of the microcanonical and canonical ensemble for certain valleys.

We solve exactly a finite-time thermodynamic optimal control problem for two nonreciprocally interacting Brownian particles translated by two harmonic traps. The controller manipulates both the center and separation of the pair. Nonreciprocal interactions generate an internal active force that couples these two channels. The optimal protocol is oscillatory, deliberately opens the dimer even when the target separation is unchanged, and can extract work during transport. A central finding is a finite critical time beyond which the external-work infimum is $-\infty$: at any prescribed duration beyond this threshold, both extractable work and output power are unbounded. Physical regularizations such as finite trap range and force saturation restore a finite optimum and convert the anomaly into optimal-protocol transitions: in the zero-target case, a hard finite range produces a first-order-like jump from the zero protocol to a maximum-range protocol, whereas smooth force saturation gives a continuous, second-order-like onset. Under finite-range constraints, the optimal protocol can further undergo multiple finite-time transitions, producing multiple work-duration kinks with no qualitative analog in prior studies.

Neutrino oscillation experiments rely on high precision neutrino energy reconstruction. A common reconstruction technique in LAr-TPCs and scintillators is via the calorimetric sum of visible particles created in the interaction. However, non-linearities in the detector response, such as Birks quenching for scintillators and recombination effects for TPCs, lead to ambiguities in the reconstruction of visible hadronic energies. Interaction-model-dependent assumptions are required to resolve these ambiguities, which introduces a bias in reconstruction of neutrino energy. This introduces a systematic uncertainty separate from the well-studied bias due to interaction-model dependent modelling of missing energy caused by, for example, the production of final state neutrons. In this work, we evaluate the interaction-model dependence of the bias caused by these material effects across multiple tunes of the GENIE, NEUT, NuWro, and GiBUU neutrino interaction event generators for cases representative of calorimetric energy reconstruction at the T2K (ND280), NO$\nu$A, MINER$\nu$A, $\mu$BooNE, and DUNE experiments. Using pure calorimetric reconstruction, our results show significant differences in the mean neutrino-energy reconstruction bias between models, at the level of $\sim$7-9\,MeV for scintillator detectors and $\sim$11-18\,MeV for argon-based detectors in the relevant energy range. The latter is shown to be reduced (down to $\sim$3.5\,MeV) when using an idealised hybrid energy reconstruction based on tracking and calorimetry. Overall, we conclude that neutrino-energy reconstruction bias due to material effects may imply non-negligible systematic uncertainties for neutrino oscillation and cross-section measurements, and discuss alternative analysis strategies to mitigate the issue.

By Godunov's theorem, linear second-order finite-difference schemes for the Fokker-Planck equation cannot preserve positivity. The Diagonal Frog (DF) framework previously bypassed this barrier using eventual positivity, but required a strict minimum time step. This paper resolves the small-step limitation using a nonlinear extension of the DF solvers. We split the second-order directional operator into a monotone M-matrix core and an antidiffusive flux correction. A Zalesak-type limiter is then applied iteratively within the implicit banded solve. The resulting Flux-Corrected DF (FCDF) schemes (variants A and B) are unconditionally positive across all time steps. Because the limiter acts on fluxes rather than point values, these schemes conserve discrete mass exactly and maintain second-order accuracy. Crucially, the limiter activates only within unresolved layers. This ensures the global $L_1$ convergence remains second-order uniformly in the cell Péclet number, avoiding the first-order degradation seen in the Chang-Cooper scheme. The method's Picard iteration is contractive under a purely convective step restriction. To support arbitrary step sizes, we develop an active-set reformulation. This solves the system using a semismooth Newton iteration, where computational cost scales only with the number of nodes where positivity binds. Finally, we introduce a defect-corrected time stepping approach that restores second-order time accuracy. Numerical experiments on Ornstein-Uhlenbeck and advection-dominated benchmarks confirm our claims.

Gravitational-wave standard sirens provide an independent probe of cosmic expansion since their luminosity distances are inferred directly from the gravitational-wave signal and, for bright sirens (BSs), the source redshifts are obtained through the identification of electromagnetic counterparts. In this work, we forecast the constraining power of future bright siren catalogues on the Hubble constant using simulated binary-neutron-star mergers detected by the Einstein Telescope with associated electromagnetic counterparts. We construct mock catalogues with different numbers of events and redshift distributions, with GW170817 as a reference BS, and analyse the resulting constraints within a flat $\Lambda$CDM cosmology. We find that, when bright sirens are used as a standalone probe, most of the information on $H_0$ is provided by low-redshift events, with the improvement in precision saturating for sources above $z \sim 1$; beyond that redshift, the constraining power of BSs is increasingly limited by the degeneracy with $\Omega_m$, which prevents further gains in precision on $H_0$. In this case, approximately $90$ low-redshift BSs are required to reach $\sigma_{H_0} \sim 1\,{\rm km\,s^{-1}\,Mpc^{-1}}$, while about $45$ are sufficient for $\sigma_{H_0} \sim 2\,{\rm km\,s^{-1}\,Mpc^{-1}}$. When external BAO information is included to reduce the $H_0 - \Omega_m$ degeneracy, intermediate-redshift sirens become more informative and the required number of events decreases substantially, to roughly $20$ and $15$ BSs for $\sigma_{H_0} \sim 1\,{\rm km\,s^{-1}\,Mpc^{-1}}$ and $\sigma_{H_0} \sim 2\,{\rm km\,s^{-1}\,Mpc^{-1}}$, respectively. These results highlight the importance of both electromagnetic counterpart identification and complementary background probes in making BSs a competitive, distance-ladder-independent test of the Hubble tension.

Fermion pairing underlies collective quantum phenomena across widely different forms of matter. In extended systems such as ultracold Fermi gases, pairing is commonly understood through the BCS–BEC crossover, where the pair size evolves from large, overlapping Cooper pairs to tightly bound dimers. In finite systems such as atomic nuclei, superconducting grains and quantum dots, however, the same pairing tendency competes with confinement, shell filling and spatial inhomogeneity, making the microscopic structure of pairs much harder to access. Here, we image pair correlations in a finite, tunable system of few fermionic atoms with single-particle resolution and full counting statistics. We observe that confinement and shell structure re-organize pairing in real space: In the weakly interacting, confinement-dominated regime, closed-shell configurations suppress correlations in the high-density trap center. Pairing is mainly observed toward the low-density surface. Open-shell systems, however, support substantially stronger central pairing. Already for surprisingly small systems, increasing either interaction strength or particle number restores a locally bulk-like Cooper-pair profile in the trap center, whereas the edge retains dimer-like correlations. By resolving where pairs form and how their character changes from localized dimers to overlapping Cooper pairs, our measurements provide a microscopic view of pairing in finite fermionic matter and connect the physics of mesoscopic cold atoms to pairing phenomena in nuclei and superconducting nanostructures.

Pauli Correlation Encoding (PCE) is a heuristic framework for binary optimisation that encodes classical variables into many-body Pauli observables. While PCE requires fewer qubits than other approaches, it relies on estimating a large number of Pauli expectation values whose signs determine the variables' values, which can incur substantial measurement overhead. Here, we introduce efficiently simulable PCE, a class of dequantised PCE realisations where all expectation values needed can be computed efficiently classically. We instantiate this idea using free-fermionic evolutions, realised by matchgate circuits, and Instantaneous Quantum Polynomial (IQP) circuits. On MaxCut, Maximum Independent Set, Multi-Dimensional Knapsack, and Max3SAT benchmarks, these methods produce high-quality solutions across problem sizes ranging from tens to thousands of variables. Our results show that PCE is naturally understood as a correlation-based optimisation framework with both quantum and classically simulable realisations. This yields a dequantised baseline for evaluating future quantum PCE implementations.

Using the TNG300 and TNG-Cluster simulations, phase space-based estimates for galaxy infall time onto clusters with $M_{\mathrm{h}} \geqslant 10^{14}~M_{\odot}$ are determined for all simulation snapshots with $z \leqslant 1$. These infall time estimates are consistent with previous work in the literature, and can be readily applied to observations of cluster galaxies, where no other estimate is feasible, based only on the galaxy's position in projected phase space. The analysis pipeline used to produce these infall time estimates is publicly released, as are the resulting data products, as well as a tutorial that outlines their use. It is anticipated that both the data products and the provided tutorial will facilitate future research within the community which require infall time estimates, and will provide an additional baseline for studies investigating the orbital histories of galaxies in dense environments like galaxy clusters.

The Epoch of Reionization Spectrometer (EoR-Spec) on the Fred Young Submillimeter Telescope (FYST) will conduct the CCAT Deep Spectroscopic Survey (DSS) to perform line-intensity mapping of redshifted [C II] emission. Atmospheric $1/f$ noise and instrumental systematics affect power-spectrum recovery. We present realistic end-to-end simulations to quantify these effects and evaluate a Filter-and-Bin (F&B) pipeline. The simulated observations include instrument response, astrophysical emission, atmospheric noise, and observing strategy. The pipeline suppresses atmospheric $1/f$ noise by about four orders of magnitude at low temporal frequencies while leaving only minor residual correlated noise. For a single EoR-Spec module operating at 50% observing efficiency, the DSS is expected to detect the combined [C II] + CO power spectrum on shot-noise-dominated scales ($k > 0.1\,\mathrm{Mpc}^{-1}$). With two modules operating at full efficiency, detections are achievable over all targeted spatial scales. The transfer function exceeds 80% at $k \gtrsim 0.5\,\mathrm{Mpc}^{-1}$ but falls below 20% at $k \lesssim 0.1\,\mathrm{Mpc}^{-1}$, indicating significant suppression of large-scale modes. These results demonstrate that the F&B pipeline is effective for recovering the shot-noise regime, while improved map-making techniques will be required for accurate large-scale clustering measurements.

The exchange-only local field factor Gx(q,omega) of the uniform electron gas is exact and universal, a single curve at every density when q is measured in units of kF and omega in units of the Fermi energy. This paper assembles the known pieces of the static Gx(q,0) into one expression, evaluates it exactly at every wavevector, and releases it as a short Python module. It rises as (q/kF)^2/4, has a large peak of 1.99 just below 2kF, passes through the exact value pi^2/6 at 2kF, and tends to 1/3. Used alone in static linear response it predicts a spin density wave at rs = 4.96 and a charge density wave at rs = 10.62. Quantum Monte Carlo shows the gas has neither. Exchange enters the measured density and spin factors G+ and G- identically, so their difference, twice the antiparallel-spin factor, contains no exchange at all and is measured to be small and smooth through 2kF. Whatever removed the exchange peak is therefore in the parallel-spin channel, where everything beyond first-order exchange is large, negative, and mirrors the exchange peak. In the measured G+ the net removal is 40 to 48 percent of the peak at rs = 1 to 10. The stability of the metallic electron gas against exchange-driven density waves is a parallel-spin effect, and the decomposition shows where microscopic calculations of each channel should go.

We give a derivation of the Gibbs measure for the focusing nonlinear Schrödinger equation (NLS) on the circle with rough cut-off. This extends earlier work by Sohinger and the second author, which proved analogous results for smooth cut-offs. Our proof is based on the perturbative expansion developed by Fröhlich, Knowles, Schlein, and Sohinger (2017), and provides an alternative proof of the recent derivation given in Lü, Nam, and Zhu (2026). To prove convergence of the explicit terms, we employ a Wigner measure approach and an inductive argument to overcome the lack of smoothness for the cut-off. In particular, we give a derivation of the Gibbs measure for the focusing quintic NLS with the optimal cut-off from Oh, Sosoe, and Tolomeo (2022).

Pulsar glitches are thought to originate when angular momentum is transferred to the crust of the neutron star from the superfluid enclosed within, mediated by vortex avalanches. This idea has been qualitatively validated in the existing literature by simulating a star with a small number ($\sim 10^{3}$) of superfluid vortices, subject to deceleration and uniform pinning. Here, we employ the Barnes-Hut approximation to simulate up to $10^{5}$ vortices in a reasonable time. Using the new setup, we probe glitches that originate in the presence of inhomogeneous pinning. The inner crust of a neutron star is expected to crack as the star spins down, relieving stresses and resulting in rearrangements within the crustal lattice. These regions become centres for pinning with large pinning energies. Many such vortex traps are expected to exist in mature pulsars like Vela. We simulate one such star and find that the rise of the glitch is now staggered, a clear signature of the trap network. In young to middle-aged stars like PSR J0537-6910, we expect quakes which result in new traps and also unpin the vortices in existing ones. We observe that such a configuration involving the simultaneous release of several traps could introduce a bimodality in the glitch-size distribution, a feature that has previously been reported for PSR J0537-6910. Our simulations also indicate that macroscopic inhomogeneities in the distribution of vortices could spontaneously develop in a star with uniform pinning sites.

The terminal-velocity paradigm has long been used to interpret the motion and infer the distances of HVCs accreting onto the Milky Way, yet its validity under realistic Galactic conditions remains uncertain. We investigate its dynamical limits by combining analytical modelling with three-dimensional hydrodynamical simulations of clouds moving through a stratified Milky Way halo. We derive a generalized equation of motion including gravity, ram-pressure drag, a phenomenological mass-exchange model capturing mass loss and growth, and Bernoulli-driven cloud expansion. Analytical solutions for constant-property clouds provide a reference framework, while the full evolution is assessed using simulations with adiabatic physics, radiative cooling, and thermal conduction. Terminal velocity is a local equilibrium but not a global attractor: dense clouds remain quasi-ballistic over most of their trajectories and approach terminal motion only shortly before reaching the Galactic disc. Hydrodynamical effects further limit the paradigm. In adiabatic flows, instabilities rapidly disrupt the cloud, rendering the terminal-velocity description inapplicable. Radiative cooling instead promotes condensation and momentum loading, maintaining strong coupling to the background gas and restoring a terminal-velocity-like regime over extended periods, while thermal conduction mainly affects small-scale structure. Synthetic observables, including position–velocity diagrams, optical extinction, and soft X-ray emission, reproduce key features of observed HVCs such as velocity bridges and compression-driven emission. We also provide direct measurements of the effective drag coefficient for infalling clouds, finding values of order unity but strongly time-dependent. Overall, the terminal-velocity paradigm is a conditional description governed by cloud structure, mass exchange, and the ambient medium.

Programming distributed quantum systems requires multiple actors to coordinate precise sequences of quantum operations, classical communication, and entanglement generation. Writing such protocols directly as distributed processes is tedious and error-prone, and subtle mismatches can cause deadlock or silently incorrect quantum states. We present Qoreo, a choreographic programming language for quantum distributed systems in which an entire protocol is expressed as single, global program (a choreography) rather than as a collection of independent actor processes. Qoreo includes a local quantum language with linear types that enforce the no-cloning principle; a choreographic language that combines local quantum computation with inter-actor classical and quantum communication; and a process language for individual network nodes. We prove type safety for choreographies, guaranteeing that well-typed programs implement well-defined quantum operations, and we define endpoint projection~(EPP), which automatically derives a network of independent processes from any choreography. We prove EPP sound and complete with respect to the choreographic semantics; as a corollary, every well-typed choreography projects to a deadlock-free process network. The metatheory of Qoreo is fully mechanized in Rocq, and we provide an extraction pipeline to NetQASM for simulation and deployment on quantum network hardware.