We propose a Floquet-engineered cold atom realization of a parity anomaly inspired anomalous Hall staircase in a two dimensional $π$-flux lattice. The effective model hosts massive Dirac fermions generated by the combined action of a time reversal symmetry breaking Floquet mass and a static inversion breaking mass offset. An additional momentum dependent scalar displacement term shifts different Dirac sectors in opposite energy directions without modifying their Bloch eigenvectors. As a result, the Berry curvature contribution associated with individual massive Dirac sectors can be selectively occupied, allowing the anomalous Hall response to evolve stepwise as a function of chemical potential or scalar displacement term. Evaluating the full lattice Berry curvature integral, we find plateau-like responses near $0$, $e^2/2h$, and $e^2/h$, corresponding respectively to the activation of zero, one, and two effective massive Dirac sector contributions. We analyze the associated low energy Dirac theory, band topology, Berry curvature structure, and two parameter response maps, and discuss a possible realization using Raman-assisted tunneling, off-resonant Floquet driving, and auxiliary AC-Stark dressing in ultracold atomic optical lattices.

We present a high-resolution hydrodynamical simulation of the formation and evolution of nuclear structures in a Milky Way-mass galaxy using the SMUGGLE multiphase ISM and stellar feedback model. The system naturally develops a bar of length $\approx5$ kpc in isolation, driving sustained gas inflows toward the center that lead to the formation of a nuclear stellar disk (NSD) and a nuclear star cluster (NSC). By considering only stars born after bar formation, we cleanly isolate the nuclear structures and recover a clear inside-out growth of the NSD. Consistent with observational studies, we find that stellar feedback induces repeated shocks that regulate the size of the nuclear gas disk and drive gas from its outer edge toward the NSC region. Over time, the NSD and NSC share similar mass growth and star formation histories, except during accretion of a massive star cluster with mass $\approx 3\times 10^{7}\Msun$, comparable to the most massive cluster observed near the NSC of NGC 4654. Our results suggest that both the evolutionary timescale of the bar (and thus of the NSD) and the accretion history of star clusters are essential for obtaining tighter scaling relations among nuclear structures and their host galaxies. Finally, our results favor a lower bulge mass for the Milky Way than in our model ($B/D\approx 0.045$) to explain the compact size of its nuclear disk.

Formulating stable numerical methods for hyperbolic systems in curvilinear coordinate with singularities, e.g. spherical coordinates, is complicated by the presence of these singularities. We present a method for constructing high-order accurate, energy-stable finite difference operators satisfying the Summation-by-Parts (SBP) property on spherical domains, extending ideas presented by [C. Gundlach, J. M. Martín-García, and D. Garfinkle, CQG 30, 145003 (2013)]. We define discrete gradient and divergence operators that mirror the continuous integration-by-parts principle, even though there is a $1/r^p$ coordinate singularity present at the origin. We explicitly construct such operators up to order six. Our operators place a grid point directly on the origin. We also review how to construct stable SBP operators that straddle the origin. We analyze the accuracy and spectral radii of these operators, and we show example evolutions of the scalar wave equation to demonstrate the advantages of such operators.

We have conducted detailed high-resolution spectroscopic studies on three extremely metal-poor (EMP) stars HE 0401-0138, HE 1153-0518 and HE 1246-1344. For the stars HE 0401-0138 and HE 1246-1344, we have estimated the abundances of C, Na, Mg, Ca, Sc, Ti, Cr, Mn, Co, Ni, Sr and Ba along with the upper limits for Li, O, La, Ce, Pr, Nd, Sm, and Eu. For HE 1153-0518, abundances of seven light elements from C through Ni and two heavy elements, Y and Ba, have been derived, together with upper limits for Li, O, and La. Based on their observed abundance patterns, HE 0401-0138 and HE 1246-1344 are classified as normal EMP stars, whereas HE 1153-0518 is identified as a newly discovered CEMP-no star. HE 1153-0518 shows strong carbon enhancement with a high absolute carbon abundance, extreme sodium enrichment, very low neutron-capture element abundances, and a very low carbon isotopic ratio (12C/13C = 2.0). Its spectral energy distribution shows clear infrared excess, indicating the presence of circumstellar dust. The abundance pattern of HE 1153-0518 suggests enrichment by early nucleosynthetic processes, such as faint core-collapse supernovae with mixing and fallback, while the possibility of binary interaction and subsequent internal mixing cannot be ruled out. The discovery and detailed study of HE 1153-0518 add an important object to the small population of high-A(C) CEMP-no stars and provide valuable constraints on early chemical enrichment pathways and the nature of the first generations of stars.

Measuring the redshift evolution of star formation rate density is crucial in understanding the origin and evolution of galaxies and large scale structure in the universe. It is currently measured with electromagnetic probes, however, these probes often track luminosity, which is then converted to star formation rate (SFR) depending on various factors such as initial mass function, dust extinction, etc. Gravitational waves provide an independent method to constrain SFR at high redshifts by tracking the redshift evolution obtained from analysis of binary black hole mergers. In this study we explore three population models for star-formation combined with an \textit{inverse} time-delay model and demonstrate that it is possible to obtain bounds on the peak of redshift distribution with a network of upgraded LIGO detectors (such as LIGO-A#). For a year of observation, using simulated signals with a merger rate peak at $z_\text{peak}=1.5$, a network of LIGO detectors at A# sensitivity is able to constrain the peak of merger rate with a precision of $\pm 0.1$. Further, we obtain the results with a next-generation network (of Cosmic Explorer and Einstein Telescope) and conclude that the redshift distribution will be extremely well measured, with a precision of $\pm 0.02$, with future detectors.

Accurate electronic excited states are essential for photochemistry, spectroscopy and non-adiabatic molecular dynamics, but high-level calculations often scale steeply and require prior knowledge of the target state's character or symmetry. Here we show that variational excited-state optimization can be reformulated as an iterated ground-state-like problem for a low-energy subspace of the electronic Hamiltonian. Applying this variational principle to non-orthogonal Slater determinants leads to EXIDOS, an automatic method for excited state calculations controlled only by the number of states and determinants per state. EXIDOS optimizes multiple excited states simultaneously, without explicit orthogonality constraints or imposed spin and point-group symmetries. Benchmarks against FCI and state-of-the-art quantum chemistry methods show chemical accuracy for a multitude of states in N$_2$ and CO, charge-transfer states in HCl, Rydberg states in NH$_3$, double excitations and extended potential-energy curves in C$_2$, and avoided crossings and conical intersections in ethylene. These results establish EXIDOS as a low-scaling, fully variational route to chemically accurate excited states.

Atom probe tomography (APT) of organic molecular liquids is limited by poorly reproducible specimen geometry, reduced milling rates, and beam sensitivity during cryo-FIB preparation. Here we introduce a MicroCup strategy that confines liquids in a FIB-prepared nanoscale cavity prior to phase separation, reduces deposited volume to increase preparation throughput, enables reproducible specimen geometry, and minimizes beam exposure in the region of interest. Using the liquid crystals 4'-octyl-4-cyanobiphenyl (8CB) and 4'-octyloxy-4-cyanobiphenyl (8OCB) as model systems, we establish stable and reproducible field evaporation conditions, enabling the detected intact ion molecular preservation above 70% in smectic-like phases with interpretable fragmentation behavior. Comparative analysis further shows that the oxygen atom in 8OCB promotes preferential cleavage pathways associated with bond polarization under high electric fields. By inducing partial crystallization within the MicroCup cavity, distinct regions could be resolved: 8CB shows broadly similar evaporation behavior across crystalline and amorphous regions, whereas 8OCB exhibits clearer regional contrast, with smectic-like regions dominated by intact molecular or large fragments and crystalline domains producing small alkyl fragments and ether-type species. These results provide spatially resolved evidence of a solid-liquid interface in a freeze-prepared organic liquid by APT and establish a reproducible workflow for probing local phase behavior in soft materials.

The origins of sub-luminous ($L_\mathrm{γ,\mathrm{iso}} < 10^{49.5}$\,erg\,s$^{-1}$) gamma-ray bursts (GRBs) associated with broad-lined Type~Ic supernovae (Ic-BL SNe) are poorly understood, in part due to the low discovery rate and faint afterglows. Here we present the identification of the optical afterglow of Fermi-GBM-detected GRB\,260310A (AT\,2026fgk) as a rapidly rising ($>1\,$mag\,d$^{-1}$), red ($g-r=0.4$\,mag) transient using the Gravitational-wave Optical Transient Observatory, Large Array Survey Telescope, and Zwicky Transient Facility (ZTF) data streams. We present multiwavelength follow-up observations from the first 50\,days, which reveal that GRB 260310A/AT\,2026fgk was sub-luminous ($L_\mathrm{γ,iso}=10^{48.8}\,$erg\,s$^{-1}$); it was the most nearby ($z=0.153$) afterglow identified blindly by an optical survey; and that it is one of the brightest afterglows ever observed at X-ray, optical, and radio (cm to mm) wavelengths. We spectroscopically confirm an underlying Ic-BL SN with properties typical of GRB-SNe ($M_\mathrm{ej}\approx3\,M_\odot$, $E_{\rm K}\approx 10^{52}\,$erg). With basic modeling of the afterglow, including the long optical rise ($\approx10^{3}\,$s), we infer either a low initial Lorentz factor ($Γ_0\approx40$) or a slightly off-axis viewing angle ($\lesssim3^\circ$). The host galaxy's mass and star formation rate are similar to the hosts of other sub-luminous GRBs. ZTF's flux-limited survey gives a volumetric rate of AT\,2026fgk-like events of $0.30^{+1.37}_{-0.29}\,$Gpc\,$^{-3}$\,yr$^{-1}$, which is consistent with the on-axis, high luminosity ($L_{\rm γ,iso}>10^{49.5}$\,erg\,s$^{-1}$) long-GRB rate. The similarity in the rates strongly constrains the prevalence of low-$Γ_0$ bursts and the beaming of the initial relativistic material in GRBs.

NGC 1052-DF2 and DF4 are two ultra-diffuse galaxies deficient in dark matter (DM), and reported as part of a remarkable linear trail of dwarf galaxies in the NGC 1052 field. Recently, NGC 1052-DF9 has been identified as the third galaxy missing DM along the trail. This structure may have been formed in a high-velocity head-on collision between two gas-rich dwarfs, known as the "bullet-dwarf" scenario. However, the trail overlaps in projection with a foreground system, the NGC 1035 group at $\sim13$ Mpc, raising suspicions that the trail is an artifact of this superposition. DF2 and DF4 have been found to be at distances of $21.7\pm1.2$ and $20.0\pm1.6$ Mpc, respectively, using the tip of the red giant branch (TRGB) method with deep Hubble Space Telescope (HST) imaging, but the distances to other trail dwarfs remain unknown. In this Letter, we use HST imaging to obtain surface brightness fluctuation (SBF) distance estimates for eight candidate trail dwarfs, as well as for the giant galaxies NGC 1052 and NGC 1035. We find that the dwarfs are all at $\sim$20 Mpc, and are not associated with the foreground NGC 1035 group. However, for DF2, we derive an SBF distance of $17.7\pm1.4$ Mpc, inconsistent with the published HST TGRB distance ($21.7\pm1.2$ Mpc). Meanwhile, James Webb Space Telescope (JWST) observations of DF2 offer a second, and potentially more accurate, TRGB distance of $17.6\pm0.6$ Mpc. While this value matches our SBF result, it is clear that uniform JWST imaging of the remaining trail dwarfs is critically needed.

Data-driven closure modeling for transport partial differential equations requires training data that are accurate, affordable, diverse, and directly tailored to the target closure fields. We develop the Generalized Forcing Method (GFM), a data-generation framework for training linear transport closure models. GFM generates such data by running simulations with a zero initial condition and an extra body force that is constructed compatibly with the reduced dynamics. This framework leads to implicit GFM (iGFM), which prescribes resolved trajectories, and explicit GFM (eGFM), which constructs a basis of admissible forcings. We apply eGFM to three linear transport closure problems: homogeneous shear flows, spatially inhomogeneous flows, and homogeneous shear flows with random coefficients. The results show that eGFM can identify accurate and stable reduced models when the reduced variables and model form are consistent with the underlying closure relation.

We study the McKean--Vlasov free energy on the unit sphere associated with the unnormalized self-attention (USA) model for noisy transformer dynamics. We prove a sharp global-minimizer dichotomy in every dimension $d\ge2$. There is a unique $β_*^{(d)}>0$ such that \begin{equation*} \frac{I_{d/2+1}(β_*^{(d)})}{I_{d/2}(β_*^{(d)})}=\frac1d, \end{equation*} where $I_ν$ is the modified Bessel function of the first kind. For $0<β\le β_*^{(d)}$, the uniform density remains the unique global minimizer up to the linear-stability threshold \begin{equation*} K_\#^{(d)}(β)=\frac{β^{d/2}}{2^{d/2}Γ(d/2)I_{d/2}(β)}, \end{equation*} and the phase transition is continuous. For $β>β_*^{(d)}$, the uniform density is not globally minimizing at $K_\#^{(d)}(β)$, so the critical coupling satisfies $K_c<K_\#^{(d)}(β)$ and the transition is discontinuous. This result generalizes the authors' recent $d=2$ work arXiv:2604.16288 to arbitrary dimension. The proof uses the sharp Beckner--Onofri/logarithmic Hardy-Littlewood-Sobolev (HLS) inequality on the sphere, together with a Funk--Hecke/Bessel coefficient computation and a degree-two quartic obstruction.

We argue that Lorentz invariance and unitarity impose sharp constraints on thermodynamic quantities. By relating thermal vacuum diagrams to forward scattering amplitudes, we derive an infinite family of sign conditions on finite-temperature observables in perturbative theories of relativistic massless bosons. In particular, we prove that all low-temperature corrections from interactions to the pressure, or equivalently the negative free energy density, of the form T^{2D-4+4k} with k>0 in D spacetime dimensions, are strictly positive. These positivity conditions are inherited by analogous terms in the entropy density and specific heat. Our results apply to any effective field theory that is free of long-range forces and descends from a weakly coupled ultraviolet completion, in which case higher-loop and higher-multiplicity thermal diagrams are parametrically subleading.

Charged dilaton black holes with a positive cosmological constant provide a useful arena in which to test how scalar hair modifies semiclassical physics in a spacetime with two Killing horizons. The Gao--Zhang solution realizes such a geometry in Einstein--Maxwell--dilaton theory by replacing a single Liouville potential, which is insufficient for asymptotically de Sitter boundary conditions, by a three-Liouville dilaton potential. Although the solution and several of its perturbative and optical properties have been studied, its temperature and heat capacity have not been examined through the same range of temperature prescriptions commonly considered for Schwarzschild--de Sitter black holes, where the absence of global thermal equilibrium motivates several inequivalent temperature definitions. We present this temperature-prescription comparison for the four-dimensional, string-coupling member of the Gao--Zhang family. We compare the standard surface-gravity temperature, the Bousso--Hawking-normalized temperature, and two effective temperatures built from the black-hole and cosmological horizons. The dilaton changes the areal radius, entropy, photon-sphere condition, and greybody problem, while the de Sitter normalization ambiguity changes radiation estimates by powers of the redshift factor. For representative parameters, the Bousso--Hawking prescription can enhance a Stefan--Boltzmann estimate of the black-hole power by one to two orders of magnitude relative to the unnormalized surface-gravity prescription, whereas the entropy-sum effective temperature can suppress the same estimate. These results identify a concrete gap in the thermodynamics of dilaton--de Sitter black holes and provide a roadmap for a full greybody-factor calculation.

We explore the capture of neutrinos and photons in the cosmic neutrino and photon background by primordial black holes (PBHs). We model this phenomenon as a gravitational interaction that effectively modifies the continuity equations for radiation and PBH densities and the cosmic expansion history. We find that the observability of this modified cosmic history is highly sensitive to PBH mass, and only extraordinarily massive PBHs would leave observable trace on the temperature and E-mode polarization of the cosmic microwave background (CMB). Specifically, Planck data restrict PBH abundance to $f_{\rm pbh}\lesssim 10^{-1}$ for PBH masses above $10^{15} M_\odot$, getting considerably tighter for higher masses. We expect substantial improvement as high-resolution measurements of larger CMB multipoles become available. A future cosmic-variance-limited experiment, with $\ell_{\rm max}=7000$, would set $f_{\rm pbh}\lesssim 10^{-1}-8\times 10^{-5}$ (for the fiducial $Λ$CDM cosmology) across $10^{13}-10^{18}M_\odot$. These constraints would be comparable to the current limits at the high-mass end of the spectrum [Carr et al, 2026]. The gravitational interaction of PBHS with the cosmic background radiation and its imprints on CMB would thus provide an independent complementary probe of extraordinarily massive PBH abundance.

Protoplanetary disks are rotating structures of gas and dust surrounding young stars, serving as the birth places of planets. Understanding the chemical evolution of organic materials in these disks is key for tracing the origins of organics in planetary systems. Formaldehyde (H$_2$CO) is the most commonly detected organic molecule in protoplanetary disks. In this study, we investigate the emission of H$_2$CO and its link to disk properties, using a sample of 20 Class II disks in the Lupus and Upper Sco star-forming regions spanning over 1-6 Myr. We analyze the H$_2$CO lines at 218.222 and 290.623 GHz observed as part of the AGE-PRO ALMA Large Program. Within this sample we achieve a detection rate of H$_2$CO of 45% (9/20), and set robust upper limits for the non-detections. We measure the excitation temperature and column density of the H$_2$CO gas in the sources with H$_2$CO detections. We combine our sample with 13 additional disks with archival H$_2$CO detections and search for correlations between H$_2$CO properties and disk parameters. Notably, we find strong correlations between H$_2$CO line luminosity and dust radius, gas radius, dust mass, gas mass, stellar mass, and stellar luminosity. This suggests that H$_2$CO emission is brighter for extended massive dust disks where H$_2$CO can form via CO ice hydrogenation on grain surfaces. We find that the H$_2$CO excitation temperature is also correlated with stellar mass and stellar luminosity, so more massive and luminous stars could increase H$_2$CO excitation.

Accessing surface quantum transport in topological insulators is hampered by residual bulk conduction arising from lattice defects. Here, we demonstrate a novel synthesis pathway for realizing high mobility $β$-Ag$_2$Te thin films where surface transport is dominant. An \textit{in-situ} vacancy engineering step as part of the molecular beam epitaxy growth process acts to modify the stoichiometry and suppress donor-type defects, enabling continuous tuning of the sheet carrier density over more than an order of magnitude through the charge-neutrality point without an external gate electrode. In the lower-carrier-density films, a fully developed $ν=1$ quantum Hall state is observed, and Landau-level energies extracted across samples collapse onto the $E_N=v_\mathrm{F}\sqrt{2e\hbar NB}$ relation, providing evidence for the massless Dirac dispersion of the top and bottom surface states. These results establish stoichiometry-driven vacancy engineering as a versatile lithography- and gate-free approach to accessing quantum Hall transport in epitaxial topological-insulator thin films.

Foundation models in atomistic machine learning encode interaction physics across diverse atomic environments, but whether that structure can be transferred when building specialist potentials at quantum-chemical accuracy remains open. Here we show that knowledge distillation from a pretrained universal machine-learning interatomic potential (MLIP), followed by coupled-cluster fine-tuning with single and double excitations and perturbative triples [CCSD(T)], transfers not only low-cost labels but a physically meaningful prior on interaction length scales, anisotropy, and the repulsive-dispersive balance, which CCSD(T) data then sharpens to quantum-chemical accuracy. For He--benzene, fine-tuning with 30% of the CCSD(T) data outperforms direct training using the full 80%; a 60% reduction in the high-fidelity compute budget. A symmetry-adapted perturbation theory (SAPT)-informed adaptive short-range/long-range architecture further lowers the validation MAE from 0.75 1/cm to 0.49 1/cm. Across a circumarene series of polycyclic aromatic hydrocarbons (PAHs), swapping the MLIP teacher under an otherwise identical pipeline changes the coronene error by an order of magnitude while leaving the larger PAHs stable, direct evidence that distillation transfers physical structure, not labels alone. Together, these results identify the choice of pretrained teacher as a primary design axis for data-efficient quantum-chemical-accuracy potentials, alongside architecture and training protocol.

When a quantum system passes through an unstable fixed point the local dynamics reduces to the inverted harmonic oscillator (IHO). It exponentially amplifies along one quadrature while squeezing the other, producing macroscopically extended quantum states from microscopic zero-point fluctuations. We realize this dynamics with a Bose-Einstein condensate on an AtomChip. Radio-frequency dressing flips the transverse harmonic confinement into an IHO. Through phase-space tomography we follow the full Wigner function of the evolving quantum state, observe sub-vacuum squeezing of 10.6(1.3) dB, and test coherent reversibility by time-reversing the IHO evolution. Matter-wave interference between the two daughter clouds confirms quantum coherence over timescales far beyond the initial expansion. Our experiment establishes ultra-cold atoms as a clean, controlled, many-body platform for unstable quantum dynamics opening a route to force sensing with time-reversal-based coherence certification and to analog studies of the amplification of quantum fluctuations in inflationary field dynamics.

In this paper we apply Hirota's bilinear method to the scalar and coupled Ablowitz-Ladik systems in the defocusing dispersion regime under the assumption of a background amplitude $0<ρ<1$. We first establish, in the scalar case, the correspondence between the Hirota's parameters and the spectral parameters of the inverse scattering transform. Then we show that when the Hirota parameter associated to the discrete eigenvalue is chosen outside the range corresponding to a discrete dark soliton, novel solutions of the Ablowitz-Ladik system emerge. In general, these solutions are singular, but there exists a class of time-periodic solutions for which it is possible to choose the soliton parameters so that the breathers remain regular on the lattice for all times. We also discuss the interactions between a dark soliton and a regular breather, and between two regular breathers. For the coupled Ablowitz-Ladik system, by including in the background discrete, counter-propagating plane waves, we use Hirota's method to derive novel Akhmediev-type (i.e., space-periodic) discrete breathers which are regular for all times. Finally, taking the limit of the discrete Akhmediev breathers as the period approaches infinity (i.e., as the wavenumber approaches zero) we obtain novel rogue wave solutions of the coupled Ablowitz-Ladik system.

Thermonuclear electron-capture supernovae (tECSNe) are a potential fate of certain intermediate mass stars forming ONe cores at the end of their evolution. Simulations suggest that these explosions are a viable alternative to collapse, yet no synthetic observables exist that allow for their identification among observed transients. We present first of their kind synthetic observables of a tECSN simulation, aiming to establish whether these explosions can occur in nature, and investigate potential observational signatures to separate them from similar transients such as pure deflagrations in CO white dwarfs. We carry out 3D photospheric phase and 1D late phase simulations using the radiative transfer code Artis. As input, we use a tECSN explosion simulation and a CO deflagration simulation with comparable $^{56}$Ni production, both computed with the Leafs code. Both models have similar observational characteristics, akin to SNe~Iax-like events. The tECSN ejecta model are characterized by a $M(^{56}\mathrm{Ni})/M_\mathrm{ej}$ ratio $25\%$ lower than that of comparable CO deflagration models. At early times, the tECSN model shows a slower decline in the red colors compared to the CO deflagration due the greater amount of Ti and Cr synthesized in the tECSN explosion. At late times, the tECSN model exhibits an exceptionally strong $12.8\,μ$m Ne II emission line, that strengthens substantially over time, whereas its strength remains largely unchanged in the CO deflagration. Our results suggest tECSNe could potentially result in SN~Iax-like transients. Importantly, we find no features that are in tension with existing observables. So far, there are no indicators that unambiguously and robustly separate tECSNe from deflagrations in CO white dwarfs. Nonetheless, our work highlights the potential importance of the mid-infrared wavelength range for distinguishing possible explosion mechanisms.

Future electron-positron Higgs factories require excellent jet energy resolution to perform precision measurements of Higgs boson couplings to quarks and gluons. Although homogeneous crystal calorimeters provide remarkable electromagnetic energy resolution, their strongly non-compensating response makes hadronic energy reconstruction particularly challenging. In this work, software compensation techniques are investigated for CRILIN, a longitudinally segmented Cherenkov crystal electromagnetic calorimeter based on PbF$_2$ crystals. Using Geant4 simulations of pion showers, it is shown that shower-shape observables are strongly correlated with the fraction of deposited energy reconstructed in a CRILIN module. Simple event-by-event corrections based on the shower transverse RMS and longitudinal center-of-gravity already yield a substantial improvement in hadronic energy reconstruction. A ParticleNet Graph Neural Network exploiting the full three-dimensional shower topology achieves significantly improved performance with respect to simple energy sum reconstruction. Under realistic assumptions for the downstream hadronic calorimeter, the GNN-based reconstruction reduces the effective CRILIN contribution to the combined calorimetric resolution to approximately $(1 ~\mathrm{GeV}/E \, \oplus \, 12\%/\sqrt{E[\mathrm{GeV}]}\,\oplus\,2.5\%)$, therefore preserving an excellent combined ECAL+HCAL performance. The dependence of the result on the assumed HCAL resolution is also studied and found to be limited within the range considered. These results show that highly granular crystal calorimeters can recover a large fraction of the information lost because of their non-compensating response through software-based compensation techniques, achieving an excellent energy resolution on hadrons in a combined ECAL+HCAL system, making them promising options for future collider experiments.

The Nancy Grace Roman Space Telescope (Roman), set for launch as early as September 2026, will conduct wide-field infrared imaging surveys with unprecedented spatial resolution and cadence, enabling the discovery of millions of astronomical transients. Hence, it is necessary to have automated pipelines for generating alerts in place so that the telescope can begin discovering reliable transients and variable objects soon after it is launched. However, no real Roman data currently exist, making the development of such pipelines difficult. In this work, we present a machine learning model $RuBR$ and a general methodology for distinguishing genuine transient and variable detections from spurious (bogus) detections within the RAPID pipeline. In particular, we present three models using this methodology: $RuBR_{comb}$ trained and tested on combined locally injected and OpenUniverse2024 transients, $RuBR_{loc}$ trained on locally injected transients and tested on OpenUniverse2024 transients, and $RuBR_{DA}$ that combines locally injected transients with a fraction of OpenUniverse2024 transients in domain-adaptation mode for training. This paves the way for strategies to adapt the $RuBR_{comb}$ model to real observations in the absence of any ground-truth labels during the early phases of the Roman mission. While the image differencing pipeline continues to be improved, our experimental results demonstrate the effectiveness of the proposed approach and its promise for robust real-bogus classification in the Roman era.

An ab initio framework using density-functional theory has been developed to predict hydrogen solubility in both pristine and defective \b{eta}-SiC. This study is motivated by the critical need for accurate hydrogen permeation models in fusion reactor designs, where predicting hydrogen permeation through tritium permeation barrier (TPB) materials is essential. Although silicon carbide is one of the leading candidates for TPBs, experimental permeation values vary widely due to differences between ideal single crystals and real, defect-containing materials. First principles calculations are employed to quantify the effects of interstitials, vacancies, and nonstoichiometric (amorphous) structures on hydrogen behavior in \b{eta}-SiC. Our results show that hydrogen solubility is significantly enhanced in carbon-rich nonstoichiometric amorphous structures and silicon vacancies compared to hydrogen occupying interstitial sites in pure \b{eta}-SiC.

Tight bounds on quantum sample complexity and quantum query complexity have been known for various computational problems in the literature, whereas tight bounds on quantum time complexity (i.e., the size of quantum circuits) remain unresolved. In this paper, we provide a framework to establish lower bounds on the quantum time complexity for testing permutation-invariant properties of quantum states, via a reduction from quantum sample complexity. As an application, we obtain a series of matching lower bounds when given sample access to the input quantum states, including: 1. The SWAP test due to Buhrman, Cleve, Watrous, and de Wolf (Phys. Rev. Lett. 2001) is time-optimal to estimate the purity $\operatorname{tr}(ρ^2)$ and the inner product $\operatorname{tr}(ρσ)$. 2. The Shift test due to Ekert, Alves, Oi, Horodecki, Horodecki, and Kwek (Phys. Rev. Lett. 2002) is time-optimal to estimate the high-order functionals $\operatorname{tr}(ρ^k)$. 3. The productness tester for multipartite pure states due to Harrow and Montanaro (J. ACM 2013) is time-optimal. 4. The LMR protocol due to Lloyd, Mohseni, and Rebentrost (Nat. Phys. 2014) is time-optimal to implement the reflection operator about a pure state. 5. The samplizer due to Wang and Zhang (IEEE Trans. Inf. Theory 2025) is time-optimal for pure states. 6. The estimator for pure-state trace distance and fidelity due to Wang and Zhang (ICALP 2026) is time-optimal. To the best of our knowledge, this is the first method that allows us to systematically establish tight lower bounds on quantum time complexity.

Photon loss in optical channels fundamentally limits long-range reliable quantum communication. A standard approach to overcoming this limitation is the use of quantum repeater nodes, which typically perform experimentally demanding non-Gaussian operations. However, whether Gaussian repeater protocols can enhance quantum communication rates over bosonic attenuation channels has remained open. In this work, we prove a no-go theorem for Gaussian quantum repeaters in a quantum network. Specifically, we show that any repeater chain composed of Gaussian operations, homodyne measurements, and arbitrary classical communication cannot enhance the quantum capacity of a pure-loss attenuation channel beyond that achievable by direct transmission. Our proof introduces a generalisation of $k$-extendibility to a notion of fractional extendibility for Gaussian states and establishes some of its useful properties, thereby providing a powerful framework for analysing Gaussian quantum networks.

A strongly interacting chain of Majorana fermions realizes the supersymmetric tricritical Ising phase, with supersymmetry (SUSY) extending into a symmetry-broken ordered phase adjacent to the tricritical point. Although the signatures of SUSY at the tricritical point are well understood, their behavior in the gapped phase remains less clear. Here, we address two key questions: how SUSY manifests in the gapped phase and what is the nature of the excitations in this phase. We show that, in the thermodynamic limit, a conventional SUSY diagnostic that remains finite at the tricritical point diverges immediately on the Ising side, yet decays continuously to zero deeper in the gapped phase, signaling the persistence of SUSY. Focusing on the lowest excited states in the supersymmetric gapped regime, we find that the excitations consist of soliton-antisoliton pairs separating distinct ordered regions. Each soliton binds an emergent localized Majorana mode, and together the pair forms a nonlocal Dirac fermion. The occupation of this Dirac mode distinguishes eigenstates with even and odd fermion parity.

Valley-polarized excitons in two-dimensional transition metal dichalcogenides (TMDs) offer a promising platform for quantum applications, yet the addressability and decoherence of these states remain fundamental challenges. Here, by developing a first-principles electrostatic embedding approach and performing large-scale GW plus Bethe-Salpeter equation calculations, we reveal novel excitons that emerge in TMD monolayers when supported by a ferroelectric twisted bilayer hBN substrate. We predict two competing low-energy excitons whose ordering depends on the dielectric environment: optically dark, charge-transfer excitons, and quasi-one-dimensional Wannier excitons with linear optical dichroism. The spatial localization of Wannier excitons, together with intervalley exchange interactions in monolayer TMDs, splits valley-degenerate excitons by about 3~meV without external magnetic fields. Our ab initio calculations clarify the role of the interfacial twist angle and the spatial localization of fringe fields, establishing design rules for engineering long-lived two-level systems in TMD monolayers supported by ferroelectric substrates.

Light-induced superconducting-like states have been reported in several classes of correlated materials. From a theoretical point of view, the induction of $η$-pairing is a promising route to nonthermal superconductivity. Numerical studies of photo-doped Mott systems revealed $η$-pairing states with very high effective critical temperatures. These investigations were however restricted to particle-hole symmetric states in large-gap Mott insulators, while the experiments were performed on strongly correlated metallic systems. It is thus relevant to explore if $η$-pairing also exists in non-particle-hole symmetric setups and in photo-excited metallic states. Here we use steady-state nonequilibrium dynamical mean field theory combined with a strong-coupling impurity solver up to third order to investigate this issue. We find that in the strongly correlated regime with large Mott gap, and for low effective doublon and holon temperatures, $η$-pairing is robust against changes in the total filling and an imbalance in the doublon and holon density. An asymmetry in the effective doublon and holon temperatures can however strongly suppress the order parameter. In photo-doped metallic systems with a three-peak structure in the local density of states, $η$-pairing can be realized in set-ups with positive doublon and holon temperatures and a population inversion in the low-energy quasi-particle band.

We propose a general Floquet-engineered scheme for phonon lasing that enables a continuous transition from conventional lasing to phase-locked squeezed phonon lasing. Focusing on a solid-state platform based on color centers embedded in a circular hexagonal boron nitride (hBN) membrane, we demonstrate that a mechanical oscillator coupled to principal and ancilla spins, and controlled via effective Floquet driving simultaneously exhibits squeezed-state amplification and cooling dynamics, leading to the emergence of a stable squeezed phonon laser. We analyse the steady-state properties of the system, including the lasing threshold, mechanical occupation, emission spectrum and second-order correlations. Furthermore, we show that Floquet engineering can realize phase-locked lasing while enabling controlled quadrature squeezing, thereby providing a simple yet effective route toward squeezed lasing in quantum mechanical systems. Our results offer new insights into the generation of squeezed phonon lasers in solid-state platforms, with potential applications in quantum metrology.

We investigate continuous gravitational-wave (CW) emission from rapidly rotating, non-axisymmetric, isolated neutron stars admixed with self-interacting fermionic dark matter (DM) and hosting DM-induced equatorial deformations (``dark mountains''). In particular, we develop a formalism that describes how DM accumulation inside the star changes its structure, how dark mountains arise from an anisotropic distribution of DM inside it, and how the star's moment of inertia and thus the amplitude of its GW emission is increased compared to that of an ordinary neutron star. Moreover, using results from all-sky searches for CWs from non-axisymmetric neutron stars performed with LIGO O3 data, we place the first constraints on the DM-induced ellipticities $\varepsilon$ of DM-admixed neutron stars across the full GW frequency range analyzed by LIGO and for a range of self-interaction strengths. With the same data, we also exclude portions of the DM-mass/self-interaction coupling strength parameter space that would have produced detectable GW signals in LIGO O3 data. We rule out at best (at worst) couplings $g\gtrsim10^{-5.5}$ ($g\gtrsim 10^{-4}$) for DM-admixed neutron stars with ellipticities $\varepsilon=10^{-7}$ ($\varepsilon=10^{-9}$) at distances $d=1$ ($d=10$) kpc away for DM masses of $m_χ\in[0.1,10]$ GeV. Furthermore, we show that even larger regions of this parameter space will become accessible to next-generation detectors, such as Einstein Telescope and Cosmic Explorer, with exclusions as strong as $g\gtrsim10^{-6}$ for neutron stars located $d=10$ kpc away for $\varepsilon=10^{-7}$. Our results demonstrate that searches for CWs naturally provide a direct probe of dark mountains sustained by DM-admixed neutron stars.