Papers

We investigate a novel class of boosted-object signatures at the LHC, where a high-$p_{\text{T}}$ fat-jet contains an identifiable hadron or quarkonium state originating from rare or semi-exclusive decays. Unlike conventional boosted jet studies, which focus on multi-prong partonic substructure, our approach probes hybrid configurations such as $W^{\pm}\to\pi^{\pm}\gamma$, where a localized hadronic or quarkonium signal is embedded within a collimated jet. By fine-tuning the signature-oriented, pre-trained Sophon AI model optimized for large-radius jets, and combining it with an event-level BDT and a soft-drop-mass shape fit, we obtain an expected 95% CL upper limit of ${\cal B}(W^{\pm}\to\pi^{\pm}\gamma)<2.78\times10^{-5}$ for $450\,\mathrm{fb}^{-1}$ in our nominal setup. This study serves as a first proof-of-principle demonstration of the “hadron-in-fat-jet” paradigm; substantial gains in sensitivity are expected from improved trigger strategies, additional production channels, and dedicated taggers, while the methodology itself is broadly applicable to a wide range of rare Standard Model processes and searches for light or exotic resonances at present and future collider experiments.

Defensive pressure on the ball carrier is a fundamental component of soccer tactics. Existing pressure measures often involve additional modeling assumptions, which may reduce interpretability. In this study, we quantify defensive pressure as the opponent minimum arrival time to the ball-carrier location, computed from a physics-based motion model. Using synchronized event and tracking data from all 306 matches in the top division of the Japan Professional Football League during the 2023 season, we analyze the statistical characteristics and temporal evolution of this quantity during ball-possession intervals. The results show that the opponent minimum arrival time tends to decrease during possession and to increase again at the start of the next possession after ball release. We also find that possessions starting under stronger defensive pressure tend to yield smaller ball progression, and that, for intentional open-play passes, possessions ending under stronger pressure are more likely to be lost. These findings indicate that minimum arrival time provides an interpretable and physically grounded measure of immediate defensive pressure on the ball carrier. The proposed framework provides a simple and interpretable baseline for quantifying pressing dynamics from tracking data.

We present a full-relativistic waveform model for extreme mass-ratio inspirals (EMRIs) by self-consistently combining the effective one-body (EOB) formalism with the Teukolsky equation. The model incorporates analytical, mass-ratio-informed geodesic solutions within a deformed Kerr metric into the source term of the Teukolsky equation, establishing a direct connection between finite-mass-ratio orbital dynamics and gravitational-wave emission. The resulting frequency-domain formulation is coupled to a high-performance solver for the homogeneous Teukolsky equation, enabling rapid evaluation of the tens of thousands of modes required for accurate EMRI waveforms. We generate waveforms and radiation fluxes for generic Kerr orbits and investigate the influence of finite-mass-ratio corrections beyond the test-particle limit. The results show that mass-ratio-dependent deformations produce measurable modifications to radiation fluxes, and accumulated waveform phases over observationally relevant timescales. Our framework provides a generic-orbit EOB–Teukolsky waveform model for future space-based GW data analysis.

We analytically study the Widom line and supercritical crossover of noncommutative charged AdS black holes. Treating the noncommutative parameter $\alpha$ perturbatively, we compute thermodynamic quantities and the scaled variance $\Omega$ in both canonical and extended ensembles. The Widom line is identified as the extremum of $\Omega$. Using a Landau expansion near the critical point, we derive the two symmetric crossover branches $L^{\pm}$, which obey $\delta T\sim \left|\Delta Q\right|^{\beta+\gamma}$, $\delta S\sim \left|\Delta Q \right|^\beta$ in the canonical ensemble and $\delta P\sim \left|\Delta T\right|^{\beta+\gamma}$, $\delta \rho\sim \left|\Delta T\right|^{\beta}$ in the extended ensemble. These scaling relations conform to the mean-field universality class ($\beta=1/2$, $\gamma=1$), and the noncommutative parameter only shifts subleading amplitudes without altering the universality class. Numerical verification and complete supercritical phase diagrams are also presented using supercritical crossover lines. Our results show that noncommutative corrections preserve the mean-field universality of black hole supercriticality.

This paper presents a focused investigation of a conservative chaotic system, specifically within the context of a two-dimensional harmonic potential well. We analyse the emergence of chaos from a straightforward, non-chaotic harmonic potential well when subjected to perturbations introduced by two Gaussian-like terms in the system's Hamiltonian. The Gaussian-perturbed system serves as a foundation for further inquiries rooted in the cymatics mechanism. In this study, we examine the effects of deformations arising from Gaussian perturbations on the development of chaotic dynamics. These deformations are produced through various configurations of Gaussian bumps in different geometric shapes, along with the modulation of the amplitude of the perturbed term shifting from positive to negative values.

We present an $\textit{ab initio}$ framework for predicting resonant inelastic X-ray scattering (RIXS) in optically pumped materials. Our methodology is based on the Kramers-Heisenberg formula for the double-differential cross section formulated using the results of the Bethe-Salpeter equation (BSE) from many-body perturbation theory. To extend this approach to the time domain, we incorporate non-equilibrium charge-carrier distributions obtained from real-time, time-dependent density-functional theory (RT-TDDFT). Generalizing the RIXS implementation with respect to arbitrary polarizations, allows us to consider different orientations of incoming and outgoing light. We demonstrate our method's capabilities by studying RIXS at the K-edge of graphite for various non-equilibrium charge-carrier distributions, representing different delay times after optical pumping. Our results reveal angular dependencies in $\pi$- and $\sigma$-orbital-derived spectral regions, in good agreement with experiment.

In this paper we clarify the relation between Geometric Thermodynamics and Information Geometry based on the Fisher matrix. On the macroscopic odd-dimensional contact manifold of thermodynamic variables, we introduce for the first time a metric, whose pull-back on the isoentropic symplectic submanifolds transverse to the Reeb field is Kählerian. The pull-back of such metric on equilibrium states, that are lagrangian submanifolds, is the Fisher Hessian. Then we consider the Souriau-like Thermodynamics that uses Calabi-Vesentini (CV) manifolds as Kaehlerian microscopic event manifolds and the Killing moment maps as observable functions. A systematic use of the theory of compact abelian structures and the setup of Special Kähler Geometry in which CV manifolds are encoded allows us to perform the explicit integration defining the partition function for any entry in the CV Tits Satake universality class. The additional actions completing the abelian structure are non linear Casimir functions of the Killing moment-maps and suggest a generalization of Souriau thermodynamics that partially breaks the isometry group symmetry by means of the non vanishing mean values of the Casimir functions in a manner similar to the spontaneous magnetization in ferromagnetism. Our new exact Gibbs distributions provide the analogue for Cartan Neural Networks of the Gaussian probability distributions in flat space used in conventional Machine Learning.

The BCS-motivated idea of Weinberg and Salam on dynamical EW symmetry breaking is revived: The Higgs sector of the EW gauge model of three fermion flavors (families) is replaced with the chiral gauge $SU(3)_f$ quantum flavor dynamics (QFD) strongly coupled at a huge scale $\Lambda$. I. With all chiral fermions in flavor triplets the anomaly freedom demands the welcome BSM extension of the SM fermion sector by one EW-sterile neutrino $\nu_R$ per flavor. II. The QFD distinguishes flavors by generating at strong coupling the chirality-prohibited (i.e. calculable) fermion masses: Three different Majorana masses $M_f \sim \Lambda$ of $\nu_R$, and three different, arguably small Dirac masses $m_f$ of SM fermions degenerate for all species in each flavor. 1. Complete spontaneous breakdown of $SU(3)_f \times U(1)$ by $M_f$ implies: (i) All flavor gluons acquire self-consistently masses $\sim M_f$. (ii) There is the $\nu_R$-composite pseudo-NG Majoron. (iii) There are three very heavy $0^{+}$ $\nu_R$-composite Higgs bosons. 2. Spontaneous breakdown of the EW $SU(2)_L \times U(1)_Y$ symmetry to $U(1)_{em}$ by $m_f$, in sharp contrast with the Higgs mechanism, implies: (i) The $W$ and $Z$ bosons acquire masses $\sim g(\sum m^2_f)^{1/2}$ and $\sim (g^2+g^{'2})^{1/2}(\sum m^2_f)^{1/2}$ respectively, defining the effective Fermi scale $v=246 \rm GeV$. (ii) There are three SM-fermion-composite $0^{+}$ Higgs bosons $h_f$ at this scale. III. The UV-finite EW dynamical perturbation theory of Pagels and Stokar splits the flavor-degenerate masses of SM-fermions by their electric charges and the ratios $m_f/m_{W,Z}$. Six Majorana neutrino masses are calculable by seasaw.

We investigate late-Universe dynamics in which the dark matter component is described by axion particles. The proposed framework departs from the standard $\Lambda$CDM paradigm due to a small fraction of axions driving the system away from thermal equilibrium. We analyze the evolution of the axion energy density using both a kinetic and a classical field approach, yielding an identical macroscopic evolution equation for the dark matter density. We emphasize that the BGK parameter is introduced phenomenologically at the kinetic level and this does not supply an independent microscopic derivation. The present work therefore explores the phenomenological consequences of late-time, out-of-equilibrium axion production rather than claiming a completed microphysical model. The resulting scenario modifies $\Lambda$CDM dynamics in the late Universe (specifically at $z \lesssim 1$), while asymptotically recovering the standard baseline at earlier cosmic epochs. We compare the theoretical predictions of our formulation against a comprehensive suite of late-Universe datasets. Our statistical analysis reveals that when the SH0ES local calibration is included, the collisional axion model becomes significantly favored over $\Lambda$CDM, yielding a best-fit Hubble constant of $H_0 \simeq 73~{\rm km\,s^{-1}\,Mpc^{-1}}$. Ultimately, this cosmological scenario successfully accommodates local distance-ladder measurements while maintaining excellent agreement with Baryon Acoustic Oscillation data from the DESI Collaboration.

The Central Molecular Zone of the Milky Way is shaped by the interplay of bar-driven inflows, shocks, and star formation. At Galactic longitude l=1.3, gas inflowing along the near-side dust lane has been proposed to interact with the CMZ boundary and overshoot above the Galactic plane, making this a key site to investigate how large-scale gas dynamics regulates star formation. We aim to investigate the presence of Class I methanol maser emission in this transitional region, testing whether large-scale gas interactions in the CMZ can trigger widespread maser activity via star formation or shocks. We conducted a dedicated search for the 36.2 and 44.1 GHz Class I CH3OH maser lines, along with the 48.4 GHz thermal transition, using the Yebes 40m telescope. We complemented these data with archival data from the Herschel-HiGAL survey and the CHIMPS2 survey to explore links between masers, shocks, and star formation. We detect widespread 36.2 GHz maser emission and two candidate 44.1 GHz masers in a region extending several parsecs. The brightest maser has an isotropic luminosity 0.9x10^-3 L_Sun, placing it among the most luminous Galactic Class I masers. Thermal CH3OH and SiO emission extend over mapped area of 24 pc, with both species showing enhanced fractional abundances. CO position-velocity analysis further shows that the masers are associated with an extended velocity feature at VLSR~100 km/s. We conclude that the observed masers are primarily associated with shock-processed gas in a kinematically complex bar-CMZ interface region. Large-scale gas interactions are likely to play an important role in producing the maser emission, although a subset of the masers may also be linked to shocks driven by local star-formation activity. This region therefore provides a promising Galactic analogue of shock-dominated Class I CH3OH maser environments observed in nuclear regions of barred galaxies.

Monochromators are routinely used in Transmission Electron Microscopy and Electron Energy Loss Spectroscopy, to improve both spatial and energy resolution. State-of-the-art monochromators, however, are complex instruments that typically require additional electron optical correctors, limiting their implementation to the high-end, most expensive microscopes. Miniaturized monochromation relying on purely electrostatic fringe fields has recently been proposed as a means to realize a simpler and thereby more cost-effective and easier to operate high-resolution monochromator. Here, we present a design for such a compact, fully electrostatic fringe-field based monochromator. Our design consists of a superposition of an Einzel lens with a series of electrostatic deflectors and is entirely based on dimensions that can be realized with MEMS fabrication technology. Thanks to mild mechanical and electrostatic potential tolerances, the MEMS-fabricated electrodes can be passively aligned and only need seven regular power supplies. We present an analysis of spectral broadening due to diffraction in our monochromator design as well as particle simulations including stochastic Coulomb interactions. This analysis shows that our design can achieve a resolution of 19 meV while maintaining 128 pA of beam current and thus potentially achieve energy filtering comparable to state-of-the-art monochromators. Our MEMS monochromator could therefore bring the application of energy filtering into the domain of SEM and specifically allow higher resolution imaging in chromatic-aberration dominated low-voltage SEM.

Traditionally, atomistic simulation has been constrained by the computational scaling limits of ab initio methods and the parameterization overhead of empirical force fields. The recent emergence of universal machine learning interatomic potentials has significantly mitigated these bottlenecks, offering near-quantum accuracy and generalizability across diverse chemical spaces at a fraction of the computational cost. However, this shift has relocated the bottleneck to the human dimension: time-consuming mechanical processes, such as input preparation and data analysis, now dominate the research lifecycle. We introduce Paimon, a Platform for Agentic Integration in Materials Optimization and Nanoscale-simulations. Through hundreds of trials on an expert-level liquid electrolyte simulation, we show that Paimon substantially improves the reliability of agentic workflows by suppressing silent errors: plausible yet physically incorrect results. Paimon accommodates a new capability without modifying the agents already present, which we demonstrate by integrating an externally developed scientific agent. As an agent harness for atomistic simulations, Paimon affords researchers a continuous, science-centric workflow throughout the entire simulation lifecycle.

Artificial intelligence is rapidly advancing materials characterization, yet most applications in electron microscopy rely solely on image contrast, overlooking the chemical and experimental context that shapes image formation. This limitation makes defect classification inherently ambiguous, as similar contrasts can arise from different materials or imaging conditions. Here we develop a context-aware learning framework that integrates image-derived contrast with metadata describing composition, beam energy, and detector geometry. Using a systematically constructed dataset of ~55 million simulated patches spanning 576 cases across 96 doped monolayer transition-metal dichalcogenides, we show that conditioning on contextual variables transforms defect classification from an ill-posed image-only task into a well-posed, physically grounded problem. The framework achieves over 98% accuracy on simulations and near-human agreement on experimental data, with a 94% reduction in posterior entropy. By emphasizing contextual grounding over architectural complexity, this approach links experimental image contrast to the underlying chemical and imaging conditions, supporting physically grounded defect assignments and a general pathway toward multimodal AI models for autonomous materials characterization.

We demonstrate that in highly magnetized pair plasma nonlinear long-wavelength X-modes experience wave collapse/breaking, whereby the wave undergoes severe spatial steepening, driven by nonlinear modifications of the refractive index and strong ponderomotive forces. The collapse/wave breaking occurs in a narrow parameter regime, when the fluctuating part of the magnetic field exceed the guide field, and plasma magnetization is close to the current starvation regime. This regime is naturally achieved in highly magnetized neutron stars, magnetars. Breaking during a fraction of the dynamic timescale, and quickly generates high-k modes. The initial EM energy, spread over large spatial scales, is squeezed into these highly localized, short-wavelength (yet macroscopic) singular pulses. The corresponding electromagnetic “foam” spectrum is red, $E_k \propto k^{-2}$, while the particles' spectrum is exceptionally hard, $f(\gamma) \propto \gamma^0$ The wave collapse produces short bright EM pulses - astrophysical Fast Radio Bursts. The highest energy particles may produce short contemporaneous high energy bursts.

Decomposing active galactic nucleus (AGN) emission from host-galaxy light is essential for identifying AGN-dominated systems and accurately deriving host-galaxy physical properties. However, estimating AGN contributions from multi-wavelength photometry remains challenging due to inherent parameter degeneracies in spectral energy distribution (SED) fitting. In this work, we establish a unified framework for estimating AGN contribution fractions and host-galaxy properties by combining complementary diagnostics: SED decomposition with two independent fitting codes, CIGALE and GRAHSP, and deep-learning-based imaging decomposition. We apply this framework to galaxies in the COSMOS-Web field using multi-wavelength photometry from the ultraviolet to the far-infrared. We calculate the AGN contribution fraction in the JWST/NIRCam F150W filter and compare the SED-derived estimates with independent AGN fractions obtained from deep-learning image decomposition. Our results reveal significant degeneracies in current SED-fitting approaches based on empirical or theoretical AGN templates and demonstrate that incorporating independent morphological information can help break these degeneracies and improve the reliability of AGN and host-galaxy property estimates.

Inspired by the $P$-wave molecular interpretation of the recently observed vector state $G(3900)$, we analyze the production of its possible pseudoscalar partner, denoted here as $G_0(3900)$, via the radiative decay $Y(4230) \to \gamma G_0(3900)$. The $G_0(3900)$ is interpreted as a $P$-wave molecular state with quantum numbers $J^{PC}=0^{-+}$, dominated by the $D\bar{D}^{\ast}/\bar{D}D^{\ast}$ components. Although not yet experimentally established, such a structure is expected to appear near the $D\bar{D}^*$ threshold and to exhibit characteristic production patterns. The decay is assumed to proceed through a triangle mechanism. Depending on the model parameters and the binding energy of $G_0(3900)$, the resulting branching fraction lies in the range $\mathcal{B}(Y(4230) \to \gamma G_0(3900)) = 3.8 \times 10^{-5} - 3.3 \times 10^{-4}$. Our results offer a pathway to search for signatures of $G_0(3900)$ in radiative channels and also provide a test of the consistency of loop-mediated radiative decays with a molecular description of the $Y(4230)$.

Longitudinal \(Z\)-boson production is strongly suppressed in collinear \(e^+e^-\) annihilation in vacuum due to current conservation and helicity selection. We show that this suppression is lifted when the incoming leptons are nonperturbatively dressed by an intense circularly polarized plane wave. The dressing produces two distinct effects. The Volkov quasi-momenta shift the collision invariant and allow an initially subresonant collision to reach the \(Z\)-boson pole, whereas the Volkov spinor prefactors generate additional Dirac structures in the neutral current. In the collinear geometry, the field-quadratic contribution to the \(n=0\) harmonic obeys a helicity-selection rule: it vanishes identically for the transverse states (\(\lambda=\pm1\)) of $Z$-boson and survives only for the longitudinal state (\(\lambda=0\)). At sufficiently large \(\xi\) along the physically allowed \(n=0\) resonance trajectory, this helicity-selective contribution becomes dominant, simultaneously driving the growth of the total rate and the enrichment of the longitudinal helicity fraction. We further show that incident-energy asymmetry does not appreciably shift this crossover, because its apparent enhancement of the light-front denominator cancels in the dominant spin-summed matrix element. Instead, the asymmetry controls the laboratory-frame boost of the resonantly produced \(Z\) boson. These results identify a nonlinear helicity-selection mechanism that separates laser control of resonant kinematics from laser control of electroweak-boson polarization.

Kling-Gupta efficiency ($\mathrm{KGE}$) is a model performance evaluation metric widely used in hydrology, but its properties as a statistical estimator have remained unexplored. We formalize the Kling-Gupta loss $L_\mathrm{KG} = (1 - \mathrm{KGE})^2$ in an extremum estimation framework (maximizing $\mathrm{KGE}$) for multiple linear regression. We give explicit formulas showing that Kling-Gupta regression scales the ordinary least squares (OLS) coefficient vector by a variance-inflation factor depending on sample variances and covariances. Its predictions reproduce the training set response variance, unlike OLS's variance reduction, while both maintain the response mean and achieve the same sample correlation. We prove that no estimator simultaneously maximizes Nash-Sutcliffe efficiency ($\mathrm{NSE}$) and $\mathrm{KGE}$: OLS maximizes $\mathrm{NSE}$ but not $\mathrm{KGE}$, whereas Kling-Gupta regression maximizes $\mathrm{KGE}$ at the expense of $\mathrm{NSE}$. We establish almost-sure convergence of the Kling-Gupta estimator to well-defined population limits. The training and test set performance metrics for both estimators converge asymptotically to identical limits (different for OLS vs. Kling-Gupta). In a single-predictor model with fixed intercept, we identify conditions where a global minimum of $L_\mathrm{KG}$ does not exist because of discontinuity at zero slope. This work establishes a mathematical foundation for $\mathrm{KGE}$-based estimation and clarifies its effects on predictive performance in hydrologic modeling.

Scientific knowledge advances through within-country and cross-border scientific activities and collaborations, influenced by funding and strength of research enterprise. Sudden declines in research funding, for example from Federal sources in the United States (US) 2024-25, adversely impact on scientific collaboration. How rapid declines in funding affect the science enterprise and the magnitude of impact need to be analysed. Past studies have modelled the global scientific system as complex collaborative networks of entities and studied its topology and dynamics. However, these studies have not undertaken compensation analysis to real-world shocks that have produced rapid declines in scientific research funding. In this study we examine the effect of the sharp declines in the US Federal funding on cancer science research enterprise globally. We model the cancer science ecosystem as a 5-layer multiplex network of collaborative linkages between 233 countries and territories in grants and clinical trial co-investigations, paper co-authorships, co-inventions and patent co-ownerships. We quantify information flow in the multiplex system through network efficiency. Proposing a framework for compensation analysis, we show that sharp declines in US Federal funding for research degrade global information exchange in science, imposing outsized compensatory burdens on country groups such as the European Union (EU) and BRICS (Brazil, Russia, India, China and South Africa). However, we also show that if other countries provide more support for international collaborations, there is an opportunity to remodel the cancer science system to be more resilient to future shocks.

This chapter introduces the fundamental principles of metrology and the concept of measurement uncertainty. It explains the role of measurement in engineering and manufacturing, outlines the distinction between error and uncertainty, and presents standard methods for evaluating uncertainty, including the GUM framework, uncertainty budgets, and Monte Carlo simulation. Practical examples and industrial standards are discussed to illustrate real-world applications.

We demonstrate that quantum algorithms can be used to model classical stochastic simulations as the measurement process is inherently random. To illustrate, we solve the classical Lorenz system with stochastic behavior using a Python random number generator. We compare the classical stochastic Lorenz system with the measured output of the quantum algorithm.

Entanglement-assisted (EA) stabilizer codes enhance the rate of error correction in relation to codes with no pre-shared entanglement. Meanwhile, bosonic error-correcting codes, such as the Gottesman-Kitaev-Preskill (GKP) code, can be concatenated with qubit stabilizer codes to significantly reduce the logical failure probability of those stabilizer codes. First, we combine the above two concepts to propose an EA version of the qubit-into-oscillators concatenated code that chains an EA-stabilizer (outer) code with a GKP (inner) code. As an example we present a three-qubit EA-repetition concatenated with a GKP code. Second, we propose an EA version of the non-Gaussian oscillator-into-oscillators concatenated code that chains a GKP (outer) code with an EA-stabilizer (inner) code. As an example we present a GKP code concatenated with a three-qubit EA repetition code that uses two maximally entangled modes (emodes) and suppresses the variances of both position and momentum quadrature errors of a data mode. Furthermore, we generalize the latter example to a family of GKP code concatenated with a $n$-qubit EA repetition code that uses ${n-1}$ emodes and suppresses the variances of both position and momentum quadrature errors of a data mode by a factor ${1/n}$.

This paper develops an agent-based model of climate-related human migration that links repeated environmental shocks to individual migration decision-making through the joint evolution of perceived risk, aspirations to migrate, and migration capability. Building on the aspirations-capabilities framework, the model represents migration as an emergent outcome of two opposing dynamics: shocks increase perceived risk and raise aspirations to move, while simultaneously eroding wealth and reducing the capability to do so. This interaction generates non-linear mobility patterns, including immobility under rising climate stress. Agents are embedded in a spatially heterogeneous shock environment, and their migration capability is further shaped by local conditions and diaspora support. Results show that more frequent shocks can initially increase migration pressure but eventually trap vulnerable agents in place as resources decline. Climate shocks amplify existing income inequalities in mobility outcomes, with lower-income agents more likely to become trapped or remain acquiescently immobile, while higher-income agents retain greater flexibility to migrate or choose voluntary immobility.

Tropical Pacific sea-surface-temperature (SST) variability spans interacting timescales, with the ENSO as its dominant interannual expression. Yet the dynamical structure organizing this variability and underpinning extended-range predictability remains difficult to extract from high-dimensional observations. Koopman operator learning offers spectral coordinates for nonlinear dynamics, yet finite geophysical records often produce dense, sampling-sensitive spectra whose physical content is ambiguous. We show that this apparent redundancy reflects coherent operator-level structure. Combining kernel Extended Dynamic Mode Decomposition with residual minimization and pseudospectral analysis, we use the Koopman eigenvalue relation as a physics-informed consistency test to organize learned spectra. Applied to ERA5 and HadISST tropical Pacific SST anomalies, the residual landscape identifies 19 robust residual-minimum frequencies with coherent spatial modes that persist across products and sampling realizations. Together, these modes define a compact Koopman backbone spanning low-frequency modulation through quasi-biennial components, including ENSO-band variability. The surrounding spectral cloud is structured by integer powers and nonlinear combinations of this backbone, forming a residual-ordered Koopman hierarchy. The backbone reconstructs substantial Nino3.4 variance and enables skillful out-of-sample forecasts, with greatest gains at 8-18-month leads. By embedding dynamical consistency into physics-informed operator learning, the framework turns opaque spectra into robust, interpretable and predictive representations of tropical Pacific variability.

Urban populations are increasingly exposed to extreme heat events such as heatwaves, which can be exacerbated in cities due to the urban heat island (UHI) effect. With the aim of developing adaptation strategies, recent years have seen a growing interest in deploying high-resolution measurement networks using low-cost devices (LCDs), which enable the evaluation of intra-urban temperature distribution and its impacts at an unprecedented spatial resolution. However, the reliability of LCD measurements has been called into question, especially regarding potential overheating due to inadequate radiation shielding. In this study, we develop a statistical method to correct temperature biases based on short-wave radiation using a generalized additive model (GAM) and then apply it to LCD measurements in the urban climate networks of the cities of Bern, Lausanne, Neuchatel and Zurich (Switzerland). To that end, we first calibrate the correction procedure to the LCD models used in each city using an intercomparison field study, in which the LCD models are collocated next to a professional automated weather station (AWS) operated by MeteoSwiss in the rural surroundings of Bern. Then, we evaluate how these corrections can influence two climate indices, namely the number of tropical nights and the number of heat warnings issued in each city according to MeteoSwiss heat warning system. The findings suggest that the current AWS underestimate the heat warnings, whereas some LCD models likely overestimate them due to radiative errors. Nevertheless, uncorrected LCD measurements still provide a more reliable estimate of urban temperatures than AWS located outside urban settings. The insights can guide selection of LCD models for new monitoring networks and support the application of model-specific radiative bias corrections to existing LCDs, enabling more accurate assessments of heat and its impacts.

Integrated modeling of ARC H-modes has been conducted to assess the feasibility of high-performance scenarios compatible with divertor detachment. The analysis incorporates self-consistent evolution of impurity radiation and density profiles, demonstrating that fusion power levels approaching a GW can be achieved while maintaining divertor temperatures below 2 eV with Ar seeding. Sensitivity studies reveal a strong dependence of fusion power on the separatrix density, with performance spanning 750-1000 MW, and a weaker dependence on enrichment factor and pedestal density. Alternative seeding strategies using Neon have also been explored. Plasmas with Argon seeding consistently access H-mode, providing the highest fusion power and detached divertor operation, whereas Neon seeding leads to lower performance (600-850 MW) and less robust H-mode access, due to excessive core impurity accumulation. A small W impurity peaking has been found, with decreasing values at higher Zeff. Further analyses incorporate reduced momentum transport modeling, and sensitivity studies of neoclassical impurity transport, confirming the robustness of the results. Overall, these findings support the viability of high-performing H-mode operation in ARC, ensuring divertor protection, enabled through Argon and Neon impurity seeding.

Context . Extremely metal-poor (EMP) stars are formed from gas clouds enriched by one or a few supernova explosions belonging to the first stellar generation and this very limited number of sources of metal enrichment is suitable to produce peculiar chemical patterns that give birth to stars with anomalous chemical composition. Among the EMP stars, r-II stars are characterised by an over-abundance of the heavy elements with respect to iron. Aims . In the search for apparently young, metal-poor stars, we serendipitously selected TYC 170-1218-1, which turned out to be an EMP star, enhanced in neutron capture elements over iron. Our aim is to obtain a detailed chemical inventory for this exceptional object. Methods . We investigated high-resolution spectra observed with UVES at the VLT telescope and Mike at the Magellan Clay telescope. We derived the abundance of 33 elements using the MyGIsFOS code and an ATLAS 9 model atmosphere. Results . The star is an EMP with [Fe/H] = -3.52. It is enhanced in the $\alpha$ elements, as EMP stars usually are. It is an r-II star with [Eu/Fe] = +1.84 and [Th/Fe] = +1.85. The star is also poor in carbon with respect to iron. The quality of the spectra was insufficient for us to detect uranium. Kinematically the star belongs now to the Galactic halo, but it joined the Milky Way during the Sequoia accretion event.

Extensive list of 4+4-dimensional Manin triples that was presented recently can be used to find new solutions of supergravity equations via Poisson-Lie T-plurality. To get the solutions we start with 1+3-dimensional flat backgrounds on Poisson-Lie groups corresponding to semi-Abelian Manin triples. For application of the Poisson-Lie T-plurality we identify Manin triples that form various decompositions of the same Drinfeld double. Beside flat backgrounds and plane-parallel waves solving supergravity equations, plurality transformation also produces curved backgrounds with torsion satisfying (generalized) supergravity equations. Many of the Poisson-Lie transformations can be understood as homogeneous Yang-Baxter deformations. Of special interest are the non-unimodular deformations leading to solutions of generalized supergravity equations.

Holography of Information (HoI) and the island formula are two recent approaches to the black hole information loss paradox that yield different Page curves. The difference between the Page curves has been argued to be rooted in the algebra that each approach focuses on. In this paper, we study the candidate algebras for the CGHS model. For the gravitational completion constructed here and under assumptions analogous to those made in previous HoI literature, we establish HoI for the CGHS model coupled to a massless scalar by constructing the radiative phase space and asymptotic algebras at future null infinity. We prove that the quantum state of the right-moving modes can be recovered from an arbitrarily small neighbourhood of the past endpoint of the right future null infinity. We then argue that island reconstruction is incompatible with exact commutativity of the left and right radiative algebras. We discuss the possible distinction between the HoI and island approaches for the CGHS model.

Diffeomorphism invariance is a central feature of general relativity. Without external reference structures, matter and geometry must be specified relationally, with respect to internal subsystems serving as reference frames. In quantum gravity, these reference systems must themselves be treated as quantum, motivating the use of quantum reference frames. In this work, we address how such a relational description could be formulated within linearized quantum gravity. To this purpose, we introduce quantum reference fields, i.e.,sets of four dynamical scalar fields whose stress-energy tensors enter the gravitational constraints. These fields extend the notion of quantum reference frames to local field-theoretic reference systems, allowing matter and gravitational degrees of freedom to be described relationally with respect to physical quantum systems whose states cannot be sharply peaked on definite field configurations. By generalizing the perspective-neutral construction of quantum reference frames, we show that relational, gauge invariant observables admit reduced descriptions in the perspective of each quantum reference field, and we derive the unitary transformations relating them. The resulting unitary maps implement local quantum coordinate changes between different internal perspectives, and act on the linearized gravitational field with an analogous structure to a linearized diffeomorphism, but with the classical gauge parameter replaced by a physical quantum field. Finally, we construct a relational von Neumann-type measurement scheme, showing how the corresponding reduced observables can be accessed operationally from the perspective of a quantum reference field.