Papers

The concept of multiple, long-delayed feedback systems is introduced and discussed with reference to a paradigmatic model. We analyse how the resulting chaotic dynamics is affected by the delay distribution. Via a mean-field approach, we show that a spatio-temporal representation equivalent to the one developed for the single-delay can be extended to this wider class of dynamical systems. Numerical simulations are complemented by a theoretical study based on a multiple-scale analysis, which, in the vicinity of a Hopf bifurcation, allows mapping the initial model onto a complex Ginzburg Landau equation. As a result, we find that the only relevant feature influenced by the multiple delays is the size of the coherent spatio-temporal structures which, in turn, depends exclusively on a generalized variance of the delay distribution.

The OSIRIS-REx mission acquired spatially resolved (2-10 m spot sizes) visible-near infrared (VNIR) and thermal infrared (TIR) spectra across four candidate sampling sites on asteroid (101955) Bennu: Nightingale, Osprey, Sandpiper, and Kingfisher. To quantify heterogeneity across a small body (about 500 m radius) like Bennu, we explore remotely observed spectral data to draw conclusions about the mineralogical composition and key physical processes that drive surface variability. We derive diagnostic band parameters from the OSIRIS-REx Visible and Infrared Spectrometer and the OSIRIS-REx Thermal Emission Spectrometer datasets to quantify compositional and physical variability across sites and assess their mineralogical context. The VNIR spectra exhibit similar overall reflectance shapes but systematic differences in spectral slopes and the 2.74 micron OH absorption. TIR emissivity spectra reveal modest but statistically significant shifts in the Christiansen Feature, silicate stretching, and bending band positions, indicating differences in silicate composition, hydration state, and Mg/Fe relative abundance. Principal component analysis separates each site into distinct clusters in multivariate band-parameter space, whereas K-means clustering identifies intra-site spectral sub-populations. Welch's Analysis of Variance and Hotelling's tests confirm that band-parameter variations between sites are significant. These results reveal that Bennu's surface preserves measurable spectral heterogeneity at 2-10 m scales, with site-to-site variations in hydration indicators and silicate band positions. The spectral properties of Nightingale encompass the full range observed across all four sites, establishing a remote sensing baseline for contextualizing laboratory analyses of the returned sample within Bennu's broader composition diversity and alteration history.

Photoelectrochemical (PEC) cells are a compelling route to solar-driven chemical energy storage and feedstock synthesis, yet their deployment is hindered by coupled losses spanning light absorption, carrier transport, interfacial charge transfer, and semiconductor-electrolyte matching. Existing models address these losses in an architecture-specific manner and fall short of quantitative experimental diagnosis or actionable design guidance. Here, we introduce a unified loss-analysis framework applicable to both built-in junction (BIJ) and semiconductor-electrolyte junction (SEJ) photoelectrodes within a consistent set of physically meaningful parameters. The framework delivers current-voltage curves and efficiency metrics under ideal and real conditions, constructing efficiency maps to delineate theoretical limits and material-selection windows. Critically, by fitting experimental current-voltage data, it enables quantitative energy-loss decomposition into thermodynamic, optical, recombination, and interfacial contributions, pinpointing performance bottlenecks in real devices and mapping them directly onto optimization strategies such as co-catalyst integration or nanostructuring. Energy flows are visualized through Sankey diagrams, providing an intuitive picture of how incident solar energy is absorbed, dissipated, or converted into chemical output. Validated against state-of-the-art literature results spanning solar water splitting, CO2 reduction, NH3 synthesis, and solar redox flow batteries, the framework further enables systematic comparison of photovoltaic-grade absorbers (e.g., Si, perovskites) with intermediate-bandgap semiconductors (e.g., hematite, BiVO4), identifying key factors limiting each material class. Together, these capabilities support a paradigm shift from empirical optimization to mechanism-informed rational design of high-efficiency PEC energy-conversion systems.

Pure two-qubit entanglement is usually characterized by scalar quantities such as concurrence. Here we show that it also has a natural geometric form. In the Pauli correlation tensor, maximally entangled states appear as improper orthogonal maps between two local Bloch spheres. These maps are roto-reflections. For partially entangled pure states, the same roto-reflection geometry is recovered after separating the contraction associated with concurrence. We call the corresponding geometric object the Entanglement Roto-Reflection Plane (ERRP). It organizes the maximally correlated directions of the two-qubit state and provides a covariant geometric complement to the scalar magnitude of entanglement. We further illustrate the usefulness of this geometry through partial transposition, where it provides a direct construction of the maximally entangled negative eigenvector and a geometric interpretation of negativity.

We formulate stochastic inflation in an open quantum system framework. The field coarse-grained in a patch of fixed physical size, and the total momentum of that patch, form a canonical pair and act on a one-mode Fock space which we identify as the "bulk". At each time step, new comoving modes join the coarse-grained patch and the bulk has to be redefined. This redefinition produces an entangled mode that is traced over, yielding a non-unitary evolution equation for the bulk's density matrix. For a free test field in de Sitter, one obtains GKLS dynamics, generated by an effective Hamiltonian and a single non-Hermitian Lindblad operator, hence diffusion and Hubble friction originate from the same quantum channel. The Wigner-Weyl transform of the GKLS equation leads to a Fokker-Planck equation for the Wigner function, which matches the one that applies to the classical phase-space distribution of stochastic inflation. We also provide several schemes under which one can unravel the GKLS dynamics into stochastic Schrodinger equations when continuous measurements of the decoupled mode are performed, making contact with Langevin formulations of stochastic inflation. In the light-field regime, an additional overdamped reduction can be performed by integrating out the momentum variable in the Wigner distribution, leading to Starobinsky's slow-roll Fokker-Planck equation. In that regime, the purity of the patch is strongly suppressed. In contrast, for heavy fields, field diffusion is suppressed and the coarse-grained patch remains close to a pure underdamped oscillator, which prevents a classical stochastic treatment.

Classical electrodynamics in curved spacetime is formulated within a tetrad-based framework that preserves the direct physical interpretation of the electromagnetic fields measured by an observer. The formalism is applied to Schwarzschild spacetime for two distinct families of observers described in the same coordinate system: static observers and radially free-falling observers. For static observers, Maxwell equations retain their usual spherical structure, while the gravitational field introduces geometrical corrections in the radial and temporal sectors through the metric function. These corrections are interpreted in terms of proper radial distance, proper time, and the radial variation of the lapse function. For radially free-falling observers, additional kinematical contributions arise from the local radial boost relating the free-falling frame to the static one. As a consequence, charge density mixes with radial current, and the electric and magnetic sectors become intertwined in the temporal-radial projections of Maxwell equations, whereas the angular Ampère-Maxwell and Faraday equations retain the same structure found for the static observer. The weak-field and near-horizon regimes are also examined, and the results are discussed through an effective-medium analogy, in which the Schwarzschild geometry behaves as an inhomogeneous geometrical medium at rest for static observers and as a radially moving effective medium in the temporal-radial sector for free-falling observers.

While vertically-sheared stratified flows have been studied extensively, their horizontally-sheared counterparts have received considerably less attention. Yet, horizontal shear instabilities remain active even when the mean Richardson number is large or even formally infinite, and can drive turbulence in strongly stratified (low Froude number) flows at sufficiently high Reynolds number. In this work, we combine linear theory with direct numerical simulations to investigate two pathways to turbulence in low Froude / high Reynolds number horizontally-sheared flow with no initial vertical shear. In the first pathway, vertical shear emerges directly from vertically-modulated eigenmodes of the primary horizontal shear instability, and becomes unstable to secondary small-scale Kelvin-Helmholtz (KH) instabilities on the buoyancy scale at sufficiently large buoyancy Reynolds number $Re_b$. In the second pathway, a vertically-invariant eigenmode of the primary horizontal shear instability initially dominates, causing the background flow to evolve nonlinearly into a long-lived time-dependent two-dimensional (columnar) vortical flow. The vortices are subsequently unstable to secondary three-dimensional hyperbolic instabilities from which vertical shear emerges, which is finally unstable to tertiary small-scale KH instabilities on the buoyancy scale at sufficiently large $Re_b$. This shows that the emergence of vertical shear driving small-scale KH instabilities is an inevitable by-product of horizontal shear instabilities in strongly stratified flows at sufficiently large $Re_b$. However, we also find that the two pathways excite different ranges of vertical scales, which results in different peak mixing efficiencies.

Electromagnetism is one of the few core physics topics without simple two-dimensional examples to start from: the cross product and curl require three dimensions. Previous work described magnetism as a bivector field, visualized with oriented (clockwise/counterclockwise) "tiles" rather than the traditional (pseudo)vector "arrows." Here, we express Maxwell's equations in this bivector language: magnetic flux is understood as a sum along a surface rather than through it, and the magnetic field tiles encircle the boundary of an Amperian loop or ribbon in a natural way. This allows a gentle two-dimensional starting point and makes symmetry arguments natural for magnetism.

We report on a phase-based lock-in thermography approach, combined with a multilayered thermal model (often employed in thermoreflectance analysis), to measure the thermal conductivity of bulk materials and layered structures. The spatial distribution of the material's thermal phase is monitored with an infrared camera, which is locked into the frequency of a modulated laser used to heat the material. This phase distribution is then fit with a thermal model, in which properties such as thermal conductivity are extracted as fit parameters. This approach enables non-contact, front-side measurements, which are insensitive to surface roughness. The technique does not strictly require the application of a transducer layer, but we highlight the practical benefits of applying a removable adhesive layer to serve as a near-surface absorber. We demonstrate the efficacy of the method by measuring materials with thermal conductivities that span over three orders of magnitude (approximately 1 W/m/K to > 2000 W/m/K).

Wave turbulence describes the statistical dynamics of dispersive waves with weakly nonlinear interactions. While the classical kinetic equation captures the mean evolution of the wave spectrum, the study of its fluctuations due to finite-size effects and intermittency requires a probabilistic framework for space-time trajectories of the spectrum dynamics. Following the previous large deviation theories for wave turbulence, we develop a simplification meant for qualitative and numerical predictions of measurable quantities. We derive a new large deviation principle in the case of local wave interactions. It fully characterizes typical and rare fluctuations of the spectrum. In a joint article, we obtain a theory which is a generalised form of Macroscopic Fluctuation Theory, but with 2 conserved quantities (mass and energy). In this paper, we use it to analyse the structure of the equation for Gaussian fluctuations around out-of-equilibrium spectra. In addition to the usual equilibrium contribution, we obtain long-range correlations, which can be decomposed into 3 contributions: one is driven by the flux in the bulk and another is driven by the forcing and its possible fluctuations. In addition, these contributions are computed for the first time with a method adapted to boundary conditions where only the fluxes are fixed. The results provide a general, replicable method for analyzing wave turbulence in more complex settings. Finally, the generalization of this theory to the inhomogeneous wave turbulence provides a possible explanation to the instability of the Kolmogorov-Zakharov spectra in some 1D inhomogeneous models with 4-wave interactions such as the Majda-McLaughlin-Tabak. This work opens the discussion regarding universal and non universal properties in two-point correlation functions. This opens new range of study on the phenomena of intermittency which is partially developed here.

We study the analytic structure of the QCD phase diagram by treating temperature as a complex variable. The nearest Yang-Lee edge singularities in the complex $T$ plane bound the domain of analyticity of temperature-dependent thermodynamic observables and complement the more commonly studied singularities in the complex chemical-potential plane. Our analysis combines three complementary perspectives: universal critical scaling, a first-principles extraction from lattice-QCD data, and explicit illustrations in effective models. We illustrate the resulting structure in a random-matrix model and in a quark-meson model, where the singularity trajectories can be followed explicitly. At small real chemical potential, the leading complex-temperature singularity admits an analytic expansion in $\mu^2$, while near a critical point it crosses over to the universal Puiseux form dictated by Ising critical scaling. We show that the complex-$T$ and complex-$\mu$ trajectories are controlled by the same scaling variables and mapping coefficients, so their comparison provides a stringent consistency test of critical-point searches and constrains the extent of the critical scaling regime. Finally, we analyze lattice-QCD data at $\mu=0$ using an iterated conformal-Pade approach and extract the continuum location of the nearest complex-temperature singularity. The result is consistent with the expectation that, at physical quark masses, the real part of the leading singularity lies between the chiral-limit transition temperature and the physical-mass chiral-susceptibility peak temperature, while its imaginary part remains nonzero.

Periodic equation-of-motion coupled-cluster theory with single and double excitations (EOM-CCSD) has shown promise for quantitative calculations of band structures in solids. However, its steep computational scaling has limited calculations to relatively coarse $k$-point meshes, leading to sizable finite-size errors and discrepant estimates of thermodynamic-limit band gaps in recent benchmarks. In this work, we revisit EOM-CCSD band gaps for ten semiconductors and insulators using interacting-bath dynamical embedding theory (ibDET), a systematically improvable Green's function embedding framework that enables dense Brillouin-zone sampling at modest computational cost. By pushing the $k$-point sampling up to $10\times10\times10$, well beyond the system sizes accessible in canonical periodic EOM-CCSD calculations, we significantly reduce finite-size errors and obtain stable thermodynamic-limit extrapolations. We further compare $G_0W_0$@PBE, $G_0W_0$@HF, and EOM-CCSD on an equal footing using the same numerical settings in PySCF. We find that EOM-CCSD yields a mean absolute error of 0.32 eV relative to experimental band gaps for a test set of ten semiconductors and insulators, lower than that of $G_0W_0$@PBE. For ZnO, EOM-CCSD also accurately describes the Zn $3d$-band binding energy, despite overestimating the band gap. These results demonstrate that ibDET offers a practical route to high-accuracy many-body electronic structure calculations in periodic systems.

We predict the $\eta/\pi^0$ ratio at low $p_T$ ($p_T \lesssim 3~\mathrm{GeV}/c$) using the measured charged $K/\pi$ ratio and model input from a blast-wave framework with feeddown contributions. This approach can provide improved, data-constrained background estimates for direct-photon and dilepton measurements in heavy-ion collisions. In this approach, the explicit modeling of radial flow and hadronic feeddown enables an uncertainty estimate for the low-$p_T$ extrapolation of the $\eta/\pi^0$ ratio. Using central Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV as an example, we find that the $\eta$-related decay-photon uncertainty at $p_T \approx 1~\mathrm{GeV}/c$ is of order 10% of the expected direct-photon signal.

Carbon-enhanced metal-poor (CEMP; with $\rm{[Fe/H]} \le -2.0$ and $\rm{[C/Fe]} \ge 0.7$) stars preserve information about early chemical enrichment, low-mass star formation, and the hierarchical assembly of galaxies. In this study, we have compiled an extensive literature sample of 1032 stellar carbon abundances spanning the metal-poor Milky Way halo (437 stars), 21 ultra-faint dwarf galaxies (UFDs; 102 stars), seven classical dwarf spheroidal galaxies (254 stars), three accreted dwarf galaxies (90 stars), the Small Accreted Stellar Systems (SASS; 77 stars), and eleven stellar streams (72 stars). We establish the fractions of CEMP stars for each of these systems and categories. Generally, the low-mass UFDs possess the high fractions at low metallicities, whereas the more massive classical dwarf galaxies have relatively few CEMP stars. This behavior reveals a new low-metallicity Magnitude ($M_{\rm V}$)–CEMP Fraction relation across the dwarf satellite galaxy population. The high CEMP fractions in surviving UFDs suggest their enrichment was dominated by faint supernovae, as higher energy input would likely have quenched star production. The low CEMP fractions in classical dwarfs imply predominantly in situ formation rather than assembly from smaller systems. Using $\rm{[C/H]}$ abundances, we also probe early low-mass star formation. Eight stars lie within or near the theoretical ”forbidden zone”, indicating that dust-induced cooling, alongside fine-structure line cooling, contributed to early star formation. These rare dust-cooled stars may have formed in UFD-like systems that did not survive. Overall, the metal-poor Milky Way halo appears to have assembled from many different dwarf galaxies, with CEMP halo stars being contributed by early UFD-like systems and non-CEMP halo stars by intermediate-sized halos that later formed classical dwarfs.

We describe spectroscopic tomographic weak lensing measurements (spectrotomography) for two rich clusters of galaxies, A1767 and A2065, based on extensive spectroscopy and Subaru/Hyper Suprime-Cam (HSC) imaging. These detections represent the first use of spectrotomography based on archival Subaru/HSC imaging. The measurements depend only on galaxies with spectroscopic redshifts reported here. The approach cleanly separates cluster members from the background and suppresses systematics that may be introduced by the use of photometric background redshifts. We detect the tomographic shear signals at $3.1\sigma$ (A1767) and $3.5\sigma$ (A2065). The shear signal amplitudes are consistent with the cluster dynamical (caustic) masses and they scale appropriately with source redshift. However, comparison with the first spectrophotometric detection of A2029 based on DECam imaging reveals some subtle potential systematic issues in deriving the shear signal for the relatively bright background galaxies used in the analysis. These issues may be important for understanding future more extensive applications of spectrotomography based on further Subaru imaging, as well as Euclid and LSST data. The total of three spectrophotometric detections (A1767, A2029, and A2065) sets the stage for broader application of the technique for unbiased cluster weak lensing mass determinations and potentially for a geometric cosmological test that is independent of other methods.

Adaptive networks couple the evolution of node states to the evolution of the interactions between them. In fast-adapting phase oscillator networks, a slow-manifold reduction of a pairwise microscopic model can generate effective higher-order terms in the phase dynamics. We ask whether this higher-order structure survives the dense-graph continuum limit, and whether it matters if one first reduces and then passes to the continuum, or first passes to the continuum and then reduces. We prove well-posedness and discrete-to-continuum convergence for the unreduced and first-order reduced models, and we construct the continuum slow manifold directly in a Banach-space setting. Along admissible equal-cell step approximations, the two routes give the same first-order continuum vector field, including the same pairwise correction and triplet operator, up to controlled $O(\varepsilon^2)$ remainders. A continuum mixed-derivative criterion then shows that, for suitable coupling functions, the resulting triplet operator is genuinely nonpairwise in the smooth bounded-kernel class. Thus the higher-order term is not a finite-network artefact, but persists in the macroscopic continuum description considered here.

Due to high current interest to Bose-Einstein condensation, the related topics, such as spontaneous gauge symmetry breaking, ergodic decomposition, and particle fluctuations, are intensively discussed in literature. These discussions, unfortunately, involve quite a number of controversies and confusions. The goal of the present brief survey is to clarify some of these confusions, concentrating on the principal points, such as the relationship between the conditions of Bose-Einstein condensation, the Bogolubov method of quasiaverages, spontaneous gauge symmetry breaking, ergodic decomposition, the presumed existence of nonthermodynamic particle fluctuations leading to the so-called “grand canonical catastrophe", and the requirements for system stability.

We perform a cosmological zoom-in simulation of a massive galaxy ($M_s\sim10^{10}\rm M_\odot$ at $z\sim10$) using the GIZMO code. By employing $\leq 3\rm pc$ resolution and a $3.4\rm Myr$ supernova feedback delay, we capture the feedback-free starbursts (FFB) in clusters. The simulation reproduces FFB model predictions and super-bright galaxies observed by JWST. At $z\sim10$, cold streams feed a compact galaxy ($R_{\rm e}\sim1\rm kpc$), with stellar and surface densities ($>10^5\rm cm^{-3}$, $>10^5\rm M_\odot pc^{-2}$) exceeding FFB thresholds. The global star-formation efficiency (SFE) is $\varepsilon_s\sim0.2\text{--}0.3$, associated with a fluctuating star-formation history. We identified over $10^5$ star clusters ($M_{\star}>10^{4.5}\rm M_\odot$) with a nearly scale-free mass distribution (${\rm d}N/{{\rm d}\log M}\propto M^{-1.06}$). Approximately 90% of star formation occurs in clusters, which at a given time constitute $30\text{--}40\%$ of the total stellar mass. The star formation in most of the clusters of masses $<10^7\rm M_\odot$, occurs in bursts of $<3\rm Myr$ and a local SFE $\sim0.5\pm 0.2$. Cluster metallicities ($-2.01<\log (Z/Z_\odot)<-0.45$) indicate rapid baryon recycling. Feedback-driven outflows exhibit typical temperature of $10^7\rm K$ and typical velocities of $\sim 2000\rm km\ s^{-1}$. In the highly dynamic central $1\rm kpc$, clusters undergo rapid orbital decay and merge to assemble the oblate nuclear stellar cluster. Cluster shapes range from oblate to prolate, with a triaxial median. These clusters are consistent with JWST observations, and a fraction of them may survive to yield the globular clusters (GCs) at low redshifts.

Background: An in-house dose engine independent of clinic TPS is not only a reliable tool for patient QA verification. More importantly, it plays vital role in cutting-edge research due to its flexibility in implementing new functions. In this study, we upgraded our existing beam model with using double-Gaussian distributions for both spatial and opening angle distributions of particles to obtain more accurate phase space files. It is expected to potentially improve the performance of this independent dose engine in both clinic and research at the expanded MD Anderson proton center.

This study investigates the terminal breakdown of human neurophysiological function through the lens of non-linear dynamics by analyzing the multifractal spectrum. Using Multifractal Detrended Fluctuation Analysis (MF-DFA), we quantify the temporal evolution of complexity in synchronized electroencephalogram (EEG) and electrocardiogram (ECG) time series from patients in the terminal stage. Our results reveal a marked divergence in multifractal spectrum width: while neural activity exhibits a collapse of multifractality toward a more constrained state, cardiac signals undergo anomalous spectral broadening, indicating increased non-linear fluctuations and dynamical instability. A negative correlation between these spectral widths suggests effective functional decoupling and the emergence of anti-correlated dynamics between neural and cardiac systems. Rather than reflecting a uniform physiological decline, this divergence is consistent with a body-to-brain breakdown in which peripheral dysfunction progressively overwhelms central regulatory processes. In a broader context, the observed opposing trends resemble patterns reported in other body-driven adaptive processes, suggesting that inverse dynamics across coupled systems may emerge when constraints originate from peripheral rather than central mechanisms. Ultimately, the dying process appears to represent an extreme form of cross-system disintegration, marked by the collapse of the hierarchical coordination that normally sustains integrated physiological function.

We report on the bulk multiband superconductivity and charge density wave (CDW) in HfxZr1-xTe3 single crystals. The parent compound ZrTe3 is a layered van der Waals material that undergoes a CDW transition near 63 K and exhibits only filamentary superconductivity below 2.0 K. Upon the introduction of a small amount of Hf (x = 0.02), the CDW transition temperature is reduced to TCDW ~ 53 K, while a robust bulk superconducting state emerges at Tc ~ 3.3 K, underscoring a subtle competition between CDW order and superconductivity in this quasi-one-dimensional system. Electrical resistivity, magnetic susceptibility, Hall effect, Seebeck coefficient, and specific heat measurements consistently confirm the bulk nature of the superconducting phase. The temperature dependence of the upper critical field Hc2(T) deviates markedly from single-band behavior, and it is well described by a two-band model, consistent with multiband superconductivity. Analysis of the Hall effect, and thermoelectric behavior reveal pronounced electronic anisotropy, with enhanced effective carrier masses, indicating that the subtle structural modification introduced by Hf substitutions affects the Fermi surface topology, as well as electronic correlations. Measurements of electrical resistivity in hydrostatic pressures up to ~ 2 GPa reveal that pressure drives TCDW to higher temperatures while suppressing Tc. These findings show that Hf doping can be used to fine-tune the balance between the CDW instability and superconductivity, possibly by means of chemical pressure effects, stabilizing a multiband superconducting state in Hf-doped ZrTe3.

The continuum-limit theory of dislocations in crystals predicts divergences in the elastic energy at crystal-geometry dependent limiting velocities $v_L$. The $v_L$ separate subsonic, transonic, and supersonic dislocation glide regimes and are therefore important for material strength models at high strain rates. Although it is known how to calculate these limiting velocities, there is one special case - edge dislocations with reflection symmetry, but non-vanishing elastic constants $c'_{16}$ or $c'_{26}$ - where previous methods have been notoriously slow. In this letter, we address this deficiency by deriving a computationally efficient method for determining the $v_L$ of edge dislocations with reflection symmetry which is two orders of magnitude faster than the previous method.

We constructed the 2D model of the Galaxy which initially includes an analytical bar, bulge, disk and halo. The model disk forms the outer elliptical resonance rings R1 and R2 located near the outer Lindblad resonance of the bar (OLR), as well as the inner resonance ring r located near the corotation radius (CR). As the density of stars in the elliptical rings increased, we introduced additional gravitational perturbations created by the rings. The radial component of gravitational perturbations from the elliptical rings, F_R, at a point with the Galactocentric coordinates (R, theta) was represented as a combination of three polynomials in powers R/Re or Re/R, where Re is the distance to the midline (middle) of the ring at a given angle theta. The azimuthal component of the disturbances, F_T, was calculated using the force F_R. The difference between the values of the force F_R (F_T) calculated using the numerical differentiation of the potential and using the analytical representation does not exceed 5.7% (1.3%) of the maximum value of the force F_R generated by the elliptical rings. In general, the gravity of the elliptical rings has little effect on the process of adjustment of epicyclic motions near the OLR of the bar.

Starting from our previously proposed line element and considering more “surface color” datasets, we derive a simplified version which matches experimental datasets equally well and resulted into a conformally-Euclidean line element, which is conceptually much simpler than any existing color difference metrics. The color difference is written as an Euclidean difference multiplied with a simple factor which depends on the luminance only. In a subspace with constant luminance, as considered by MacAdam, this factor becomes constant and the subspace is flat. The same holds for sufficiently large luminances. Based on this LE we derive perceptual coordinates $\left(A,l_{c},s_{c}\right)$ very similar to the CIELab $\left(L^{*},a^{*},b^{*}\right)$.

The analytic integration of single-scale Feynman integrals emerging in perturbative calculations in quantum field theories can be performed within special classes of functions, which appear as consecutive generalizations of the polylogarithm in form of Kummer-Poincaré iterative integrals over special alphabets and extensions thereof. These are the polylogarithms, Nielsen integrals, the iterated integrals over linear denominator terms, cyclotomic letters, letters induced by quadratic forms, and square-root valued letters. These integrals are solutions of first-order factorizing differential equations. They are related to specific nested sums via the Mellin transform and their expansions around $x=0$. We construct the $\mu$-extensions of these iterated integrals and the associated nested sums. We present closed form solutions or provide algorithms in the case of more involved cases to derive the respective $\mu$-extensions and study the algebras of the $\mu$-extended function spaces. Except for the case of square-root valued alphabets, the $\mu$-extension maps into the same function space polynomially in $\mu$. This is also the case for the associated nested sums. For square-root valued alphabets or sums containing central binomials, the $\mu$-extension leads to higher transcendental functions. In all other cases the $\mu$-extension preserves the Hopf algebra structure implied by the (quasi)shuffle product, by supplementing $\mu$ to the ground field.

The inner Milky Way hosts overlapping stellar populations (bar–bulge, inner thin and thick disks, and halo), complicating population assignments along the line of sight. A joint chemical–dynamical approach is required to isolate a clean field bulge sample. Metal-poor bulge stars are valuable as they likely trace the earliest phases of chemical enrichment in the inner Galaxy. We aim to characterize the alpha-element (Si, Mg) and selected Fe-peak abundances of a dynamically defined sample of bulge field stars, and to contrast these trends with the inner-halo tail in the metal-poor regime. We analyze metal-poor candidates from the Pristine Inner Galaxy Survey observed by the bulge Cluster APOGEE Survey. Using APOGEE/ASPCAP abundances (S/N >= 50), we integrate full 6D orbits in a barred Milky Way potential. Bulge membership is defined via orbital confinement using an apocenter cut and the high-density locus in the (E_J, L_z) plane, with uncertainties estimated using Monte Carlo simulations. We identify 98 stars as bulge members. The metallicity distribution spans -2.5 <= [Fe/H] <= -0.4, with a median [Fe/H] = -1.71, offset to higher metallicity than the inner halo (median [Fe/H] = -1.96). The sample follows a high-alpha sequence with slopes d[Si/Fe]/d[Fe/H] = -0.020(+0.012,-0.051) and d[Mg/Fe]/d[Fe/H] = -0.097(+0.062,-0.133). Fe-peak tracers show [Ni/Fe] ~ 0, while [Mn/Fe] declines with [Fe/H] with a mild upturn at higher metallicity. We detect no significant [Si/Fe] gradients with R_apo or Z_max (+0.010(+0.018,0.000) and +0.006(+0.022,-0.011) dex kpc^-1, respectively). Results are insensitive to Omega_p, yielding indistinguishable memberships. The chemo-orbital evidence favors an in situ origin within the inner Galaxy for the metal-poor bulge field, enriched at early times and rearranged by secular bar evolution, with a minor contribution from halo stars at the most metal-poor end.

A compact liquid hydrogen target system has been developed for the Silicon Tracker for RAdioactive nuclei Studies at SAMURAI Experiments (STRASSE) at the RIKEN Nishina Center. This target, designed for proton-induced quasi-free scattering measurements in inverse kinematics, features a customizable cylindrical cell with a volume up to 125~mL which increases the reaction rate/luminosity, and thin Mylar walls to minimize the protons' angular straggling. The cryogenic system, operated at 20~K, is optimized for rapid cool-down ($\leq$ 5~h) and empty-target measurements, avoiding long experimental dead time. This new setup will allow for high-precision studies of nuclear structure using both missing-mass and in-flight prompt $\gamma$-ray spectroscopy techniques at the RIBF facility.

Scalar fields provide perhaps the simplest playground in which to develop our understanding of quantum field theory. In this lecture, we consider what it means to write down a scalar quantum field theory and how we can give geometrical interpretations to the space of such theories: the theory space.

In our work, based on an exact solution of the Ising model on a decorated square lattice with an arbitrary number of decorating spins, we have demonstrated the fundamental possibility of describing the phenomenon of multiple magnetic phase transitions (magnetic reentrancy) in the regime of competing exchange interactions. We analyzed the magnetic behavior of the system and established the conditions for the occurrence of magnetic reentrancy. We have determined the relationships of the model parameter under which the formation of one, three, and even five magnetic phase transitions is possible, which is confirmed by a complicated magnetic phase diagram. We have also proposed a unique method for finding critical temperatures that allows for the precise determination of their number and values, including those at extremely low temperatures.

We study the unsteady dynamics of floating planar bodies undergoing lateral oscillations along an air–water interface. Scaling arguments indicate that when the viscous penetration depth and oscillation amplitude are both small compared to the body size, the flow beneath the body can be approximated by an oscillatory Stokes boundary layer, yielding a leading-order description of the hydrodynamic resistance. Using magnetic actuation, we drive the interfacial bodies harmonically and measure the amplitude response and phase lag in steady state over a range of frequencies, masses, sizes, and shapes. This frequency-response framework enables direct extraction of effective added mass and damping coefficients, which we find to be consistent with oscillatory boundary-layer theory in the limit of small interfacial deformation. The transient behavior during startup is also shown to be accurately predicted by a history integral that captures the development of the oscillatory boundary layer beneath the body. This work also establishes a simple experimental platform for quantifying unsteady hydrodynamic forces at fluid interfaces.