We define a higher-derivative generalization of Maxwell-Chern-Simons theory in $\mathcal{N}=1$ and $\mathcal{N}=2$ superspaces. In particular, the chosen higher-derivative operator is a polynomial function of the d'Alembertian of arbitrary degree, and it is introduced exclusively in the gauge sector. The main goal is to explicitly compute the one-loop quantum corrections to the superfield effective potential for these theories. This is carried out by means of background field quantization in a higher-derivative $R_ξ$ gauge. The effective potential is obtained in closed form and expressed in terms of the roots of polynomial functions.

Outside the core of the plasma, the plasma current and pressure rapidly transition to zero in a scrape-off or edge region or plasma-vacuum interface. However, existing tools for fixed-boundary magnetohydrodynamic equilibria in 2D and 3D domains $Ω$ typically prescribe the computational boundary $\partialΩ$ interior to this transition layer. We (1) argue that a more realistic and robust assumption is to define the computational boundary exterior to this transition layer, in a vacuum-like region where $J|_{\partialΩ} \sim p|_{\partialΩ} \sim 0$, (2) show that, without this boundary change, existing coil optimization routines for 3D toroidal equilibria (stellarators) should be changed to match free-boundary equilibrium requirements, and (3) derive an algorithm for a fixed-boundary 3D equilibrium solver compatible with a very general computational boundary, with conditions $B \cdot n|_{\partialΩ} \neq 0$ (not necessarily a flux surface), $p|_{\partialΩ} \neq \text{const.}$ (not necessarily an isobar), and $J \times n|_{\partialΩ} \neq 0$.

Lumens are cavities enclosed by polarized cells that are essential for organ function, from nutrient transport in the gut to gas exchange in the lungs. Defects in lumen formation are associated with severe diseases, including polycystic kidney disease and respiratory malformations. The emergence, growth, and maintenance of lumens involve a rich set of phenomena that can be framed within out-of-equilibrium physics and biological active matter, including osmotically driven hydraulic flows, coarsening-like dynamics, morphological instabilities, and mechanochemical feedbacks linking luminal pressure to tissue response. Yet experimental and theoretical efforts to study these phenomena have largely developed within specific biological systems, complicating the identification of shared physical principles across them. In this review, we bring these efforts together and present lumenogenesis within a biological physics framework in which lumens are viewed as active balloons: pressurized cavities that are inflated, sculpted, and maintained through tightly coupled active processes.

Continuum reverberation mapping (RM) is a powerful technique for constraining the accretion disk structure in active galactic nuclei (AGNs). In typical cases, the shorter-wavelength emission is used as the reference, and a positive time lag is observed since the inner, hotter regions of the accretion disk respond earlier than the cooler outer regions at longer wavelengths. However, we detect a short-timescale negative inter-band lag in SDSS~J083717.88+191647 using RM techniques, where the \textit{g}-band lags behind the \textit{r}-band emission. The light curves from the Zwicky Transient Facility reveal two distinct phases, a stabilizing and a declining phase, in which the time lags show opposite signs. Using \texttt{JAVELIN} with the $g$-band as the reference, we obtain time lags of $3.68^{+1.94}_{-2.78}$~days during the stabilizing phase and $-1.60^{+0.69}_{-0.54}$~days during the declining phase. Although negative continuum lags have been reported in a few previous studies, the present case is distinguished by its clear phase dependence and the accompanying color evolution. We attribute the observed lag reversal to a moving dust-cloud obscuration scenario, in which the cloud crossing the line of sight preferentially obscures emission from the outer longer-wavelength regions of the disk, causing the $r$-band to decline earlier than the $g$-band and thus producing the observed negative inter-band lag. Our results indicate that AGN variability may be more complex than previously thought. Future high-cadence, multi-band observations will be essential to test this dust-obscuration model and to further explore the interplay between the accretion disk emission and dust in AGNs.

Based on the ballistic macroscopic fluctuation theory, the integration of the spin correlation function (spin conductivity) is analyzed for the spin-1/2 XXZ chain in the critical regime. In the time when the magnetization of an infinite spin chain fluctuates from an initial state with a wavelength as long as the infinite length $N$, the equal-time two-point spin correlation function is scaled up to $O(1/N)$. In the state where the ballistic spin transport decays at high temperature $T$, the diffusive transport remains on a large scale. We show that the spin conductivity is proportional to $1/T$ in the limit $T\to\infty$ and its high temperature proportionality constant diverges in the case where one-quasiparticle magnetization is infinitely large. This analysis informs that the superdiffusive spin transport is driven by the $1/N$-scaled long-range spin correlation and sheds a light on the dynamic scaling in spin transport at the isotropic point.

We investigate the influence of rotation and quadrupole deformations of astrophysical compact objects on the Shirokov and Shapiro effects within the Hartle-Thorne spacetime, which describes the exterior gravitational field of slowly rotating, slightly deformed celestial objects. Using geodesic deviation equations, we analyze the oscillatory motion of neighboring test particle trajectories and show how the combined impact of angular momentum $J$ and quadrupole moment $Q$ affects the Shirokov effect. The results are compared with our previous analysis for the Lense-Thirring and Zipoy-Voorhees metrics, revealing consistent trends in the coupling between radial and azimuthal oscillations. For the Shapiro time delay, we examine two limiting configurations: (i) the Lense-Thirring frame-dragging case with $J^2=0$, $Q=0$ and $J\neq0$, where the effect persists for both positive and negative values of the angular momentum; and (ii) the static quadrupolar case with $J=0$ and $Q\neq0$, where more oblate sources produce a stronger gravitational time delay with increasing distance. We also study these effects in the Hartle-Thorne spacetime without employing the weak-field approximation, performing a full numerical analysis. In particular, we examine the mimicking effects produced by the quadrupole deformation and the angular momentum of the compact object. These results illustrate how the deformation and rotation of compact objects influence the relativistic observables in the surrounding spacetime.

On the grounds of nonadditive entropies -- appropriate for complex systems -- we investigate the electroencephalogram amplitudes of typical and ADHD children. The corresponding probability distributions are $q$-Gaussians, i.e., $ρ(x) \propto e_q^{-βx^2} \equiv [1+(q-1) βx^2]^{1/(1-q)}$, where $(q,β)$ are, respectively, the entropic index characterizing complexity and the inverse width. We show that $q$ tends to monotonically vary with $β$ for both typical and ADHD subjects, thus revealing critical behavior of the brain. Moreover, we verify that ADHD subjects have a higher complexity than the typical ones. Consistently, biomarkers for objective phychyatric diagnosis could emerge along this path. We show that $q$ tends to monotonically vary with $β$ for both typical and ADHD subjects, thus revealing critical behavior of the brain. Moreover, we verify that ADHD subjects have a higher complexity than the typical ones. Consistently, biomarkers for objective phychyatric diagnosis could emerge along this path.

Dynamical chaos is a term that encompasses a wide range of nonlinear phenomena such as turbulence, neuronal avalanches, weather patterns, and many others. However, despite much work in the field of chaos, its fundamental physical origin still remains not fully understood. In this perspective we report on recent studies showing that chaos is the realization of one of the most fundamental principles in physics: spontaneous symmetry breaking also known as spontaneous ordering. In the present context, the symmetry involved is a topological supersymmetry inherent to all continuous-time (stochastic) dynamical systems. Chaos is then truly a manifestation of order of topological origin potentially encoding a sort of long-range information hidden beneath its apparent unpredictability. We finally argue that this point of view may have far-reaching implications well beyond chaotic dynamics.

The quantum approximate optimization algorithm (QAOA) has emerged as a promising candidate for demonstrating quantum advantage on noisy intermediate-scale quantum (NISQ) devices. While various QAOA parameterization schemes exist, ranging from the original single-angle approach to the more expressive multi-angle quantum approximate optimization algorithm (MA-QAOA) and automorphic-angle quantum approximate optimization algorithm (AA-QAOA), each presents distinct trade-offs between expressiveness and classical optimization complexity. In this work, we introduce the $k$-interaction-angle quantum approximate optimization algorithm ($k$A-QAOA), a parameterization scheme that groups cost function terms by their $k$-body interaction order, providing a natural middle ground between parameter efficiency and solution quality. This approach is particularly well-suited for combinatorial optimization problems defined on hypergraphs, where multi-body interactions naturally arise in applications such as Boolean satisfiability and resource allocation with multi-party constraints. We benchmark $k$A-QAOA against standard single-angle quantum approximate optimization algorithm (SA-QAOA), MA-QAOA, and AA-QAOA on two problem classes: 3-uniform cyclic sign-alternating hypergraphs and random coefficient hypergraphs. Our results demonstrate that $k$A-QAOA achieves approximation ratios comparable to MA-QAOA while requiring significantly fewer function evaluations, thereby reducing quantum resource consumption.

Based on the conventional metric tensor and driven by a nearly constant energy density, cosmic inflation, characterized by a remarkably accelerated expansion, was proposed as an early epoch in the Universe. The energy density is typically modeled through a slow-rolling scalar field, whose potential energy dominates the dynamics. This mechanism addresses horizon, flatness, and relic problems, while also generating quantum fluctuations that are stretched to cosmological scales, leading to emergence of primordial curvatures and tensor perturbations. Despite its empirical success, significant questions remain regarding identity of the inflaton, origin of the potential, and role of quantum gravity. A quantum-deformed conformal metric that is both perturbatively and tensorially structured and expanded is employed to reexamine the dynamics of inflation, thus enabling the computation of a range of inflationary observables in presence of quantum-induced corrections. We have established a closed and internally consistent set of analytical formulas for scalar and tensor power spectra, including their spectral tilts, runnings, and the tensor-to-scalar ratio, among other parameters. The quantum corrections appear to provide a clear physical interpretation related to measure scaling and momentum-induced kinetic deformation, which facilitates modifications to the inflationary observables in a controlled and predictive manner. While maintaining the classical limits, these corrections provide a well-defined phenomenological perspective on potential quantum-gravitational structures in the early Universe.

We develop a unified description of dense fermionic matter that consistently incorporates Pauli degeneracy, interaction effects, and pairing correlations. The condition that the temperature is much smaller than the Fermi energy leads to a natural separation between Sommerfeld, Fermi-liquid, and pairing regimes, and how these contributions enter the equation of state. The resulting EOS is applied to the Tolman-Oppenheimer-Volkoff equations to analyze neutron-star structure. We demonstrate that Pauli degeneracy provides the dominant pressure, interactions determine the stiffness of the EOS, and pairing correlations produce subleading but potentially significant corrections, especially in quark matter. Implications for mass--radius constraints and modern observations are discussed.

We investigate the propagation of high-speed solar wind streams from their origin near the Sun to 1 AU using three-dimensional magnetohydrodynamic simulations. By tracking both global stream structure and individual plasma parcels, we assess how local in-situ measurements relate to the underlying plasma evolution. We find that high-speed streams are not parcel-preserving structures: commonly used diagnostics such as peak velocity, density, or temperature do not trace fixed plasma elements, and feature-based radial trends can therefore misrepresent the true evolution. Instead, velocity-based relationships provide a more robust framework for linking plasma parcels across heliocentric distances. Stream evolution is dominated by interaction regions, where compression leads to deceleration of fast wind, acceleration of slow wind, and significant heating. A boundary layer forms close to the Sun and can dominate narrow streams, biasing in-situ measurements toward lower apparent velocities. We show that three-dimensional transport, in particular latitudinal flows, redistributes mass and magnetic flux and reduces center-to-flank contrasts. While radial magnetic flux is conserved, the total field strength is not in spherical sampling geometries due to non-radial components. Finally, observed stream properties and geoeffectivity depend strongly on sampling location, stream geometry, and latitudinal magnetic deflection, introducing systematic variability and asymmetries in geomagnetic response.

We investigate the nonequilibrium dynamics and loss of coherence in a quantum impurity system using the spinless resonant level model subject to sudden quenches of the hybridization between the impurity and the metal. The survival probability (fidelity) and impurity occupation are analyzed as probes of the dephasing induced by particle-hole excitations. For finite systems, the loss of coherence loss is only apparent, as discrete spectra lead to quasi-periodic dynamics and revivals when phases realign. We show that a mixed linear-logarithmic discretization suppresses these finite-size artifacts by rendering excitation energies incommensurate, thereby reducing revivals. Starting from the exactly solvable two-level limit exhibiting coherent Rabi oscillations, we extend the analysis to large lattices, where damping and relaxation emerge. Combining analytical and numerical results, we provide a unified picture of the crossover from coherent oscillations to effectively irreversible decoherence.

We present the point-spread function (PSF) of the Extreme Ultraviolet High-Resolution Imager (HRIEUV) onboard Solar Orbiter, which observes the Sun at 174 Angstrom. This PSF provides a quantitative description of light diffracted by the mesh and mounting supporting the entrance filter, light diffracted by the mesh supporting the filter-wheel filter, as well as light that is diffusely scattered by the microroughness of the mirrors. Deconvolution with this PSF corrects the images for instrumental scattered light, substantially improving image quality and photometric accuracy. First, we determine the diffraction component of the PSF from mechanical drawings of the instrument. We find that 26% of the incoming light is diffracted, predominantly by the entrance-filter mounting and mesh. Second, we fit the diffuse scattered light using partial image occultations during the 2023-Jan-03 Mercury transit. We find that the diffuse scattered light is well described by a softened power law, which scatters 42% of light over the detector. Combined, 57% of the incoming light is redistributed over the detector by diffraction and scattering. Correcting for these effects markedly enhances the dynamic range and contrast of the observations. The intensity in bright structures intensifies by up to 40% and the intensity in dark structures decreases by up to 85 %. All images features become much clearer, facilitating a more precise scientific analysis of HRIEUV observations.

We investigate traversable wormhole solutions within a four-dimensional effective theory derived from a five-dimensional Einstein-Maxwell-Chern-Simons action with a non-minimally coupled scalar field. A warped Kaluza-Klein compactification yields an Einstein-frame theory containing a phantom dilaton, a canonical axion, a Maxwell field, and a Kaluza-Klein vector, with the couplings fixed by the higher-dimensional origin. Focusing on the Ellis-Bronnikov geometry, we construct solutions that incorporate both dyonic Maxwell and Kaluza-Klein fields. For exponential gauge couplings, the Einstein equations determine the scalar kinetic term and the combined potentials, while the remaining field equations reduce to algebraic relations fixing the individual potentials and the radial behaviour of the electric charges. We obtain a systematic classification of configurations, ranging from the pure phantom-supported wormhole to fully coupled dilaton-axion-gauge configurations. The Kaluza-Klein sector enriches the solution space with additional structure while preserving analytic tractability. These results show that regular, asymptotically flat traversable four-dimensional wormholes arise naturally from higher-dimensional scalar-tensor theories.

Blazars are promising sources of extragalactic high-energy astrophysical neutrinos, detected at energies $\gtrsim 10$ TeV by the IceCube neutrino observatory. Here, we report the first-ever broadband timing and spectral study of the flat-spectrum radio quasar PKS 1725+123, which has recently emerged as a compelling multimessenger target following its spatial association with the IceCube event IC-201021A. This triggered extensive follow-up observations from radio to VHE $γ$-rays, and a multi-episode flare was identified at a later time. During this period, the source exhibited high flux variability across all wavelengths. The {\it Fermi}-LAT analysis suggests rapid variability on timescales of less than 6 hours, implying a compact emission region with a radius of $\sim10^{16}$ cm. Our one-zone leptohadronic model shows that the high-energy $γ$-ray flux is produced by a combination of inverse-Compton scattering of external photons from the hot accretion disk and the broad-line region, while the X-ray emission is dominated by synchrotron self-Compton radiation from relativistic electrons. The secondary radiation from the hadronic cascade is found to be sub-dominant in the $γ$-ray regime, and the X-ray data constrain the maximum proton energy to $\sim 20$ PeV in the observer frame. Photopion production occurs predominantly with accretion-disk photons, resulting in an estimated muon-neutrino event rate of $\approx 0.3~\mathrm{yr}^{-1}$ during the flaring state with the flux peaking at $\sim1$ PeV. Future observations of TeV $γ$-rays by CTA and LHAASO will further constrain cosmic-ray production in this source.

Data-driven weather models have made rapid advances in recent years, reaching and in some metrics surpassing the large-scale forecast skill of operational numerical weather prediction. This progress, however, has been built almost entirely on the reanalysis data that NWP produced, while the methodological knowledge that the NWP community distilled over decades of multi-scale atmospheric modelling remains largely unused. Here we present Cast3, a generative forecasting framework that systematically absorbs NWP meta-knowledge to close this gap. Cast3 operates on variable-resolution cubed-sphere grids for scale-aware representation and constructs structurally diverse super-ensembles that sample the complementary biases of different grid discretizations, delivering state-of-the-art ensemble prediction. It further introduces generative nudging, a posterior-sampling strategy that distils the collective information of the full ensemble into a single forecast possessing both the large-scale accuracy of the ensemble mean and the mesoscale realism of a high-resolution member. Evaluated across synoptic-scale skill, spectral fidelity, station-level surface verification, and tropical cyclone prediction, Cast3 outperforms established deterministic and generative baselines across various dimensions. More broadly, these results demonstrate that the design principles embedded in computational atmospheric science offer a rich and largely untapped foundation for the next generation of data-driven Earth system modelling.

We present a theoretical model of the ionization-recombination balance in the ultracold Rydberg gas-plasma mixture, which is caused by the collective processes rather than by individual interparticle interactions. This should be well relevant to the steady-state ultracold plasmas obtained in the recent experiment [B. Zelener, et al. Phys. Rev. Lett. 132, 115301 (2024)]. As follows from our calculations, there should be a sharp crossover from the insulating phase (Rydberg gas) to the conducting one (plasma) with increase in the particle density, which closely resembles Mott transition in the condensed-matter physics.

We investigate entanglement dynamics in bipartite systems governed by inhomogeneous Hamiltonians of the form $H = H_L + H_R$, where $H_{L/R}$ acts only on the left or right region and is homogeneous within each region. Focusing on the XX chain and the transverse-field Ising chain, we derive analytical formulas for the entanglement entropy between the two regions in the hydrodynamic limit of long times. In this regime, fermions incident on the interface undergo scattering, generating entanglement between reflected and transmitted modes. The resulting quasiparticle picture is controlled by the transmission coefficient, which we obtain analytically by solving the stationary lattice Schrödinger equation. Due to the bounded dispersion, strong inhomogeneity suppresses both transport and entanglement growth. We benchmark our analytical predictions against numerical simulations in paradigmatic setups. Finally, we extend the analysis to the interacting XXZ chain using tDMRG. The numerical data show qualitative agreement with the quadratic case: entanglement growth remains suppressed in the strongly inhomogeneous limit. Notably, however, entanglement continues to increase even when transport is suppressed, at least at intermediate times.

Ultra-hot Jupiters present extreme atmospheric phenomena not found in the Solar System. These planets' daysides experience strong temperature inversions, molecular species (including H2) dissociate, and magnetism disrupts their atmospheric circulation. On their nightsides H2 can recombine and clouds may form. Spectroscopic phase curves let us measure these spatially inhomogeneous conditions, which can then be interpreted with three-dimensional (3-D) models. In this work we compare the JWST/NIRISS spectroscopic phase curve of the ultra-hot Jupiter WASP-121 b to state-of-the-art 3-D models with varying modeling assumptions, including the aforementioned physical phenomena. We demonstrate the importance of accurately accounting for the planet's radius in comparison between data and models, as it changes the implied overall planetary emission. We find that the 3-D models predict planet emission $\sim$12% higher than observed, contributing to a continued tension between measured and predicted hot Jupiter albedos. We identify multiple pieces of evidence that confirm a strong source of drag operating in this planet's atmosphere. In addition, the nightside emission spectrum is devoid of strong absorption features, which may be best explained by nightside clouds. One feature of the dataset that is not matched by the 3-D models is a trend of increasing eastward phase offset with decreasing wavelength, for wavelengths shorter than $\sim$1.4 \textmu m. This result is not consistent with reflection from dayside clouds, nor can it be explained by removing atmospheric opacity sources. Our analysis highlights the complexities in generating 3-D models and interpreting observations of ultra-hot Jupiters in the JWST era.

This textbook is drawn from notes for a two-semester graduate course in quantum mechanics. It begins with the most constrained quantum system, and recovers the rest of the subject by relaxing those constraints one at a time. The starting point is a single qubit, the smallest nontrivial Hilbert space with the strongest possible restriction on its dynamics, made concrete by a Bloch cube whose six faces are the cardinal states of a spin-1/2 system. Tensor products admit many qubits; lattices give them a place to live; time evolution sets them in motion; the continuum limit produces wavefunctions; three-dimensional angular momentum, the hydrogen atom, and perturbation theory follow; Lorentz invariance promotes the lattice of spinors to the Dirac equation; and the renormalization group asks how theories at different scales relate. Each chapter loosens one feature of the qubit while keeping the others fixed, so that the standard apparatus of graduate quantum mechanics arrives as a sequence of controlled generalizations rather than as separate topics. Discrete-to-continuous transitions recur at four scales: in Hilbert-space dimension, in real space, in time, and in coupling. The book closes by reimposing one of the original constraints, returning to a two-level system that is now a logical qubit protected by quantum error correction, with the fault-tolerance threshold appearing as an unstable RG fixed point and supplying the reason a logical qubit, independent of its underlying hardware, can exist at all.

Sophisticated Khovanov-Rozansky (KhR) description of knot invariants in the fundamental representation can be reformulated in terms of bicomplex with a simple physical meaning. Namely, the counterintuitive matrix factorization is substituted by simple operators $D$, locally constructed for every MOY resolution of a link diagram, which becomes nilpotent when the diagram has no external lines. Operators for different resolutions are related by equally simple conjugations $χ^{(\pm)}$. The KhR procedure then splits in two steps - defining ``vertical'' cohomologies of $D$, which are associated with particular resolutions and will be put at vertices of the hypercube, and conjugations $χ^{(\pm)}$, that define morphisms along its edges. As usual, standard combinations of morphisms are nilpotent, and one can define ``horizontal'' cohomologies - which are then combined into Poincaré polynomial, called KhR polynomial in application to links. This construction remains global in the sense that resulting cohomologies depend on the entire link diagram, but all its building blocks, including the operators and morphisms are local in the sense that they are defined for its particular vertices. Sometimes, this allows simple local reductions, allowing to eliminate or change particular vertices or sets of those. Along with the obvious case of Reidemeister equivalencies this happens also for antiparallel-lock tangles, what is responsible for simplification of bipartite calculus. In the $N=2$ and arbitrary $N$ bipartite cases, one can also provide global reductions transferring the local construction of the KhR double-complex to the global construction of the Khovanov(-like) single-complex.

Strong light-matter coupling gives rise to polaritons - hybrid excitations whose mixed photonic and matter character enables control over optical, electronic and chemical properties. This Feature Article surveys the main architectures supporting polariton formation, including photonic microcavities, plasmonic nanostructures, open cavities and metasurfaces, and outlines how inorganic semiconductors, organic aggregates and hybrid systems access strong and ultrastrong coupling. Key phenomena such as coherent dynamics, vibronic interactions, dark-state reservoirs and polariton-mediated energy and electron transport are discussed, together with the experimental and theoretical tools used to study them. We highlight examples where strong coupling modifies charge transport, energy flow and chemical reactivity, and we summarize emerging regimes, including intermediate and dark-strong coupling, that broaden the landscape of hybrid light-matter physics.

We study the interior of the Schwarzschild black hole which is isometric to the Kantowski-Sachs cosmological model, using a fully relational and gauge-invariant quantization framework. The physical Hilbert space is constructed via refined algebraic quantization, and quantum dynamics is recovered through the Page-Wootters formalism with a covariant POVM clock built from one of the two configuration variables, whose Hamiltonian is proportional to the momentum of the said variable. Gauge-invariant relational observables for the area of 2-spheres, the Kretschmann scalar, and the expansion scalar of null geodesic are constructed via group averaging (G-twirl) and evaluated on physical states. We find that the Kretschmann and expansion scalars remain finite throughout the black hole, while the area of 2-spheres is bounded below by a minimum value proportional to the uncertainty in the system variable, which is the other configuration variable distinct from the clock variable. In particular, the expansion scalar vanishes and changes sign at the quantum bounce, establishing a black-hole-to-white-hole transition. These results hold for any general clock whose operator forms a canonical pair with the clock Hamiltonian, and require no specific quantization scheme other than the Schrodinger representation. The singularity resolution emerges directly from relationality, the Heisenberg uncertainty principle, and the structure of the physical Hilbert space.

The atomic nucleus, viewed as a system of bound quarks, should, in principle, be described within an effective theory of low-energy quantum chromodynamics. This paper provides an overview of recently developed models that embody essential features of the desired effective theory. The Fermi gas model helps explain why the number of $d$ quarks is approximately equal to that of $u$ quarks in stable light nuclei up to ${\rm {}^{40}_{20}Ca}$. A modified bag model accounts for the deviation from this rule in heavier nuclei. With this model, the static properties of a wide range of stable nuclei can be described with reasonable accuracy. To make the most of the modified bag model, it is useful to invoke gauge/gravity duality. A refined version of duality states: ``The dynamics inside an extremal black hole in ${\rm AdS}_5$ is mapped onto the corresponding dynamics of a stable subnuclear system in ${\mathbb R}_{1,3}$''. This version of duality allows one to predict the primary decay channel of the lightest glueball. Another implication is that this framework explains why the periodic table contains a finite number of stable elements. Duality makes it possible to calculate the maximum allowed charge $Z_{\rm max}$ of stable heavy nuclei: $Z_{\rm max}\approx 82$, which is the charge of the ${\rm {}^{208}_{82}Pb}$ nucleus.

This paper develops a Hall-Sandpile model of economic instability that combines a Hall-like transversal stress mechanism with sandpile threshold dynamics on a real production-network substrate. In analogy with the physical Hall effect, where exposed flows under an external field generate stress in a transversal direction, we model economic shocks as fields that act on flow-intensive, low-redundancy, low-capacity nodes and produce systemic stress through a multiplicative conversion function. The accumulated stress drives a discrete toppling rule and an avalanche dynamics whose effective activation threshold declines with transversal exposure. The model is calibrated on annual World Input--Output Database (WIOD) production networks for 2000--2014 and simulated on the 2014 substrate (2{,}283 country--sector nodes) under three alternative propagation normalisations to avoid mechanical near-criticality from row-stochastic operators. Controlled Monte Carlo experiments over external field intensity and redundancy stress generate four ordered regimes: stable absorption, latent fragility, critical transition, and avalanche regime. Mean avalanche size and the probabilities of finite-size systemic events $\Pr(S\!\geq\!5)$, $\Pr(S\!\geq\!10)$ and $\Pr(S\!\geq\!20)$ rise jointly with field intensity and redundancy stress. Tail diagnostics show regime-dependent thickening of the avalanche distribution, but the estimated tail indices remain too high to interpret as evidence of universal power-law criticality. The contribution is therefore a finite-size, real-network description of how transversal stress activates structural fragility, not a claim of self-organised criticality in the global economy.

A fascinating approach to teaching Newton's Third Law using readily available technology is presented in this article. Magnetic forces are measured by using a smartphone's pressure sensor, two ring magnets, and common household items. Students can measure the magnitudes of forces, gain a more tangible understanding of the law, and see how 'action' and 'reaction' are quantitatively equal and opposite.

Collective strong coupling of molecular ensembles to optical cavities opens a route to modifying matter through genuinely collective electronic correlations. Yet even in the absence of a cavity, Coulomb correlations are notoriously difficult to describe, and cavity coupling adds transverse correlation channels extending over the entire molecular ensemble. Here we show that this seemingly intractable problem admits a controlled description by mapping the collective intermolecular electronic correlations to the analytically solvable spherical Sherrington-Kirkpatrick model. The resulting theory predicts two collective correlation phases, a paracorrelated phase and a spin-glass correlation phase, beyond the conventional uncorrelated molecular regime. These phases reveal an entropy-driven localization-delocalization mechanism that transfers molecular electronic states into collectively correlated cavity-dressed states. Our work establishes cavity-mediated electron correlations as a microscopic mechanism for emergent phases in strongly coupled molecular ensembles.

Imperfections in X-ray imaging systems can limit their performance, especially in High Energy Density (HED) or Inertial Fusion Energy (IFE)-relevant experiments that are typically single shot, by introducing structured, non-stationary features that overlap with the signal of interest. When the X-ray transmission is reconstructed by typical flat-field normalization, even small shot-to-shot drift of structured features imprints residual patterns onto transmission maps, degrading signal visibility and biasing measurements such as electron density, velocity and feature sizes. We investigate this limitation by modeling the artifacts as a separable feature layer and training a U-Net architecture to estimate and infer them directly from the experimental data. We compare our method against Fourier filtering and more advanced procedures like Dynamic Flat-Field Normalization (DFFN) to evaluate artifact suppression capability and signal preservation in the reconstructed transmission maps. In multiple synthetic injection tests, our Physics-Guided Deep Learning approach is able to obtain an improvement in mean Structural Similarity Index (SSIM) from 0.345 to 0.906 and from 0.0679 to 0.945, while better preserving filament profiles and reducing degradation of the filament signal during artifact suppression. Additionally, we utilize deep ensembles to obtain predictive epistemic uncertainty estimates for the U-Net based reconstruction, to ensure Out Of Distribution (OOD) robustness for this procedure.

Machine Learning surrogates for Computational Fluid Dynamics (CFD), particularly Graph Neural Networks (GNNs) and Transformers, have become a new important approach for accelerating physics simulations. However, we identify a critical bottleneck in the field: while architectures have advanced significantly, the common underlying training paradigms remain bound to naive assumptions, such as node-wise supervision and explicit Euler time-stepping. These legacy choices ignore the stiff dynamics and local flux continuity inherent to numerous partial differential equations resolution methods, such as Finite Element, Difference, or Volume (FEM). In this work, we propose a unified framework to bridge the gap between geometric deep learning and rigorous numerical analysis. We introduce three key innovations: (1) Multi Node Prediction, a stencil-level objective that predicts field values for a node's full local topology, enforcing spatial derivative consistency; (2) Temporal Correction, replacing unstable explicit schemes with a predictor-corrector via temporal Cross-Attention; and (3) Geometric Inductive Biases, leveraging 3D Rotary Positional Embeddings (RoPE) to robustly capture rotational symmetries in unstructured meshes. We evaluate this framework across three architectures (MeshGraphNet, Transolver, and a Transformer) on diverse physics datasets. Our approach yields consistent improvements in accuracy and stability, particularly in long-horizon rollouts, while producing latent representations that generalize to unseen subtasks such as Wall Shear Stress or Pressure prediction. Code is available at https://github.com/DonsetPG/graph-physics.