Grain growth is a key process in the thermomechanical treatment of metals. Recently, the presence of local residual stresses within fully recrystallized grains has attracted increasing interest in connection with shear-coupled grain boundary migration mechanisms. In this work, we provide the first direct experimental measurements of residual elastic strain variations in fully recrystallized commercial-purity iron, on the order of $10^{-4}$. Using dark-field X-ray microscopy (DFXM), we performed non-destructive three-dimensional measurements of strain and orientation variations within individual grains. Our results reveal heterogeneous strain distributions across all measured grains. In one case, we observed several isolated dislocations accommodating two second-phase particles, exhibiting a localized strain signature with no detectable long-range effect. The formation mechanisms of intragranular residual strains and their potential influence on grain boundary migration during subsequent grain growth are discussed. This work highlights the importance of accounting for such residual elastic strains in future grain growth models.

In this work, we exactly derive the solution for the gravitational field of a black hole in Eddington-inspired Born-Infeld (EiBI) gravity, surrounded by perfect fluid dark matter. We analyze how the event horizon and the black hole dimensions vary as a function of the model parameters, exploring the fundamental properties of this spacetime. Through numerical investigations, we examine the geodesics of massive particles and demonstrate the high sensitivity of stable circular orbits to the system's coupling constants.

We study estimation and inference for heterogeneous principal causal effects with binary treatments and binary intermediate variables. Principal causal effects are subgroup effects within strata defined by potential values of an intermediate variable, including effects among compliers. We propose a framework for estimating and forming pointwise confidence intervals for heterogeneous principal causal effects under the principal ignorability assumption. Several estimators are developed, and their robustness properties are characterized: one estimator is doubly robust, whereas the other two attain intermediate robustness between double and triple robustness; in contrast, principal causal effects can be estimated in a triply robust manner only. We establish large-sample theory under nonparametric smoothness conditions and analyze the bias contributions of each approach, providing insight into performance beyond the smooth setting, including in high-dimensional regimes. Camden Coalition hotspotting randomized trial are used to illustrate the methods by estimating heterogeneous complier effects.

We study discrete expressions of the form $$ T_n(g)=\sum_{i=1}^n a_i g(S_i), \qquad S_i=\sum_{j=1}^i a_j, $$ where $a_i>0$ and $\sum_{i=1}^n a_i=1$. If $g:[0,1]\to\mathbb{R}$ is a decreasing integrable function, we have $$ \sum_{i=1}^n a_i g(S_i) \le \int_0^1 g(x)\,dx, $$ from which classical inequalities can be obtained, for instance for the choice $g(x)=1-x^k$. Although elementary, this inequality admits a natural interpretation in terms of Riemann sums, Abel summation, and the probability integral transform. The aim of this paper is to present a unified perspective emphasizing that the discrete inequality is a consequence of a distribution-free continuous identity. Beyond the specific example, we establish a general discrete theorem for monotone functions and discuss connections with majorization theory and Karamata's inequality.

Contrary to conventional wisdom, intermediate photoluminescence energies can be stabilized in mixed-halide lead perovskites during photosegregation. These intermediate energies reside between those of the parent, mixed-halide alloy and fully photosegregated specimens. This demonstrates rudimentary color tuning and has practical implications for potential uses of mixed-halide perovskites in lighting applications. More fundamentally, such color tuning begs the question of how intermediate photosegregation energies arise and how they are kinetically stabilized. What follows is a study of the kinetics of terminal photosegregation energies under pulsed laser excitation. Through concerted continuous wave and pulsed laser photosegregation measurements, we develop a kinetic rationalization for how photosegregations repetition rate or duty cycle and peak fluence dependencies lead to intermediate, terminal photoluminescence energies. The developed model, in turn, explains prior observations of pulsed illumination photosegregation and offers potential insights into other, yet to be explained, phenomena such as spectral blueshifting under high intensity, pulsed illumination.

This paper investigates the Hausdorff measure of certain sets of generics in computability theory. Let $Γ$ be the Turing ideal in which we take the dense open sets. The set of $Γ$-Cohen generics has measure positive if and only if the gauge function is not dominated by every element in $Γ$, under some mild restrictions on the gauge function. The set of $Γ$-Mathias generics and the set of $Γ$-Sacks generics have measure positive if and only if the gauge function eventually dominates every element in $Γ$. This gives some comparison between the behavior of reals in the set and the measure of the set.

Qualitative research gives rich insights into the quintessentially human aspects of software engineering as a socio-technical system. Qualitative research spans diverse strategies and methods, from interpretivist, in situ observational field studies, to deductive coding of data from mining studies. Advances in large language models and generative AI (GenAI) have prompted claims that artificial intelligence could automate qualitative analysis. Such claims are overgeneralizing from narrow successes. GenAI support must be carefully adapted to the data of interest, but also to the characteristics of a particular research strategy. In this Frontiers of SE paper, we discuss the emerging use of GenAI in relation to the broad spectrum of qualitative research in software engineering. We outline the dimensions of qualitative work in software engineering, review emerging empirical evidence for GenAI assistance, examine the pros and cons of GenAI-mediated qualitative research practices, and revisit qualitative research quality factors, in light of GenAI. Our goal is to inform researchers about the promises and pitfalls of GenAI-assisted qualitative research. We conclude with future plans to advance understanding of its use in software engineering.

The synthesis of the high-$T_c$ superhydride CaH$_6$ has stimulated significant interest in understanding synthesis pathways for metastable hydrides. However, the microscopic mechanisms governing such hydrogenation reactions remain poorly understood. Here, we show that machine-learning potential molecular dynamics (MLP-MD) simulations can reproduce and distinguish competing reaction pathways leading to metastable and stable hydrides. By simulating hydrogenation reactions at CaH$_2$/H$_2$ and CaH$_4$/H$_2$ interfaces, we identify two distinct pathways that produce clathrate-type CaH$_6$ and A15-type CaH$_{5.75}$, respectively. CaH$_{5.75}$ lies on the convex hull but requires extensive Ca sublattice rearrangement and therefore forms only at elevated temperatures. In contrast, CaH$_6$ becomes kinetically accessible when CaH$_2$ is used as the precursor. The crystallographic compatibility between the Ca sublattice of CaH$_2$ and the bcc framework of CaH$_6$ enables a martensitic-like topotactic transformation that bypasses the reconstructive pathway leading to CaH$_{5.75}$. These results reveal how precursor structure and thermodynamic stability compete to determine superhydride formation pathways and demonstrate that machine-learning molecular dynamics can directly capture the kinetic selection of metastable phases in reactive materials systems.

Biological learning achieves temporal credit assignment despite sparse and imprecise feedback, often relying on neuromodulatory signals acting over space and time. Here, we introduce a learning mechanism in which error information diffuses locally through the network, similar to volume transmission of neuromodulators. This distributed modulation allows neurons to learn even in the absence of direct feedback, using the local concentration of the diffusing credit signal. Applied to recurrent spiking neural networks with sparse feedback connectivity, diffusive credit signaling improves learning across three benchmark tasks. Using eligibility propagation as a baseline learning mechanism, we show how diffusion-based modulation can provide a plausible mechanism for credit assignment in sparsely connected neural circuits.

In tokamaks, turbulence is responsible not only for the anomalous transport of heat and particles from the core to the edge, which reduces heating efficiency, but also for the generation of zonal structures (ZSs). Examples of ZSs are those with characteristic sound frequency, like the geodesic acoustic modes (GAMs). Developing a theoretical model of ZS is essential, as they contribute to the turbulence saturation and thus indirectly influence transport. In this paper, we investigate the radial structure of ZS in the frequency range of GAMs, by means of numerical simulations using the gyrokinetic particle-in-cell code ORB5. We find that radially extended coherent ZSs (labelled here as global ZSs) are non-linearly generated by the high-n part of the turbulence spectrum (with n being the toroidal mode number) by means of self-consistent simulations. We also reproduce this generation by mimicking the turbulence modes with an antenna, thus isolating the nonlinear generation mechanism.

Zero-knowledge codes, introduced by Decatur, Goldreich, and Ron (ePrint 1997), are error-correcting codes in which few codeword symbols reveal no information about the encoded message, and have been extensively used in cryptographic constructions. Quantum CSS codes, introduced by Calderbank and Shor (Phys. Rev. A 1996) and Steane (Royal Society A 1996), are error-correcting codes that allow for quantum error correction, and are also useful for applications in quantum complexity theory. In this short note, we show that (linear, perfect) zero-knowledge codes and quantum CSS codes are equivalent. We demonstrate the potential of this equivalence by using it to obtain explicit asymptotically-good zero-knowledge locally-testable codes.

Understanding the formation and evolution of the Milky Way (MW) requires detailed knowledge of its satellite galaxies. In this study, we focus on the Sextans dwarf spheroidal (dSph) galaxy, a faint, dark matter (DM)-dominated satellite, to investigate the role of tidal and baryonic effects in shaping its observed properties. Using tailored $N$-body simulations, we explore possible orbits of Sextans in different MW models to reconstruct its progenitor's properties. Our simulations demonstrate the stars in Sextans are only mildly affected by galactic tides and the stellar kinematics provide robust constraints on its dynamical mass within the half-light radius, while the tidal mass loss of its DM component depends primarily on MW mass. The recovered infall mass of Sextans ranges from $1.22$ to $3.14\times10^9\rm\,M_\odot$ for MW masses from $0.8$ to $2\times10^{12}\rm\,M_\odot$. If the DM density remained as cuspy as NFW profile, the infall mass would be smaller by a factor of 2. Although with large ranges, the possible infall masses of Sextans recovered by our simulations are consistent with the stellar mass-halo mass relation in TNG50 and abundance matching results. We find some cases for the cuspy DM density profile where the infall mass is smaller than $10^9\rm\,M_\odot$, possibly indicating that star formation in Sextans is more efficient than in other satellites. The recovered DM halo structural parameters from our simulations provide valuable constraints for future studies on the DM content and formation history of Sextans.

We consider the \textsf{Unit Interval Selection} problem in the one-pass random order streaming model. Here, an algorithm is presented a sequence of $n$ unit-length intervals on the line that arrive in uniform random order, and the objective is to output a largest set of disjoint intervals using space linear in the size of an optimal solution. Previous work only considered adversarially ordered streams and established that, in this space constraint, a $(2/3)$-approximation can be achieved, and this is also best possible, i.e. any improvement requires space $Ω(n)$ [Emek et al., TALG'16]. In this work, we show that an improved expected approximation factor can be achieved if the input stream is in uniform random order, with the expectation taken over the stream order. Specifically, we give a one-pass streaming algorithm with expected approximation factor $0.7401$ using space $O(|OPT|)$, where $OPT$ denotes an optimal solution. We also show that algorithms with expected approximation factor above $8/9$ require space $Ω(n)$, and algorithms that compute a better than $2/3$-approximation with probability above $2/3$ also require $Ω(n)$ space. On a technical note, we design an algorithm for the restricted domain $[0,Δ)$, for some constant $Δ$, and use standard techniques to obtain an algorithm for unrestricted domains. For the restricted domain $[0,Δ)$, we run $O(Δ)$ recursive instances of our algorithm, with each instance targeting the situation where a specific interval from $OPT$ arrives first. We establish the interesting property that our algorithm performs worst when the input stream is precisely a set of independent intervals. We then analyse the algorithm on these instances. Our lower bound is proved via communication complexity arguments, similar in spirit to the robust communication lower bounds by [Chakrabarti et al., Theory Comput. 2016].

ErMgGaO$_4$ is a quantum antiferromagnet wherein the pseudospin-1/2 degrees of freedom of Er$^{3+}$ decorate two-dimensional triangular planes separated by disordered non-magnetic bilayers of Mg$^{2+}$ and Ga$^{3+}$. Unlike its sister compound, YbMgGaO$_4$, our powder ErMgGaO$_4$ sample shows a clear spin glass transition near $T_g \sim 2.5$~K, about 1/6 of its Curie-Weiss temperature. We have carried out new inelastic neutron scattering measurements on these powder ErMgGaO$_4$ samples. At high energies, we observed crystalline electric field (CEF) transitions within the $J=15/2$ multiplet of Er$^{3+}$, but with the first excited CEF level sufficiently low in energy ($\sim$ 3~meV) so as to allow the possibility that virtual CEF transitions influence the exchange couplings. At E=0, we observe diffuse elastic scattering which is analysed using Warren lineshapes appropriate for two dimensional correlations. This reveals dominant 2D stripy correlations below $T_g$, coexisting with 2D 120$^\circ$-type correlations that persist above $T_g$. At low temperatures, the low energy inelastic component of the scattering shows a continuum with bandwidth of $\sim$ 0.8~meV. This dynamic magnetic spectral weight can be modeled at all $Q$, energies, and temperatures as the sum of high energy and low energy damped harmonic oscillators (DHO), with the high energy DHO defining the bandwidth of $\sim$ 0.8~meV. We use linear spin wave theory to model this inelastic scattering and to estimate its spin Hamiltonian parameters in terms of a $J_1-J_2-Δ$ model on the triangular lattice. This gives a good description of the low lying spectral weight for ErMgGaO4, and allows us to place it on the theoretical $J_1-J_2-Δ$ phase diagram with $\frac{J_1}{J_2}=0.13 \pm 0.03$ and $Δ=0.4 \pm 0.1$, which is close to the expected quantum phase boundary between the spin liquid and the stripy ordered phases.

The influence of the low-frequency gravitational waves coupled with electromagnetic waves in material media on the test masses is investigated. The propagation of coupled gravitational waves in rarefied gases and cold magnetized plasma is considered. It has been shown that under specific conditions the amplitude of the coupled gravitational waves in a media reaches values of the order of the amplitude of transverse gravitational waves from external astrophysical sources. The specific properties of longitudinal gravitational waves coupled with electromagnetic waves in a medium in relation to transverse gravitational waves from external sources are considered as well.

This paper presents bsort, a non-comparison-based sorting algorithm for signed and unsigned integers, and floating-point values. The algorithm unifies these cases through an approach derived from binary quicksort, achieving $O(wn)$ runtime asymptotic behavior and $O(w)$ auxiliary space, where $w$ is the element word size. This algorithm is highly efficient for data types with small word sizes, where empirical analysis exhibits performance competitive with highly optimized hybrid algorithms from popular libraries.

Variational inference approximates Bayesian posterior distributions by projecting onto a tractable family of distributions. While most theoretical analyses evaluate the quality of this approximation using global divergence measures, many applications rely on specific posterior summaries such as expectations, variances, or tail probabilities. We develop a geometric framework for analyzing the bias of posterior functionals under variational approximations. We show that the leading-order bias of a posterior functional is determined by its component orthogonal to the variational tangent space induced by the variational family. Functionals aligned with this space incur only second-order bias. For structured mean-field variational families we characterize the tangent space explicitly and show that it consists of block-additive functions of the parameter blocks, while interaction components determine the leading-order bias. Under standard local asymptotic normality conditions we further derive explicit asymptotic expansions for the bias of posterior functionals and show that omitted interaction directions produce first-order distortion of cross-block dependence measures. These results provide a geometric explanation for several well-known properties of mean-field variational inference, including the systematic distortion of cross-block dependencies.

Luminosity leveling to limit the event pile up is a key ingredient of the LHC luminosity upgrade, the High-Luminosity LHC (HL-LHC). For a future circular hadron collider, such as the FCC-hh, operating at a centre-of-mass energy of 70-90 TeV, synchrotron radiation becomes significant, with radiation damping times of the order of one or a few hours. The rapid shrinkage of the emittance may call for a leveling of the beam-beam tune shift or of the event pile up, as previously explored. However, the strong synchrotron radiation emitted inside the cold superconducting magnets also represents a significant heat load and is likely to limit the total beam current. In this article, we discuss a new approach, namely synchrotron radiation power leveling, where the beam energy is adjusted during a physics store, either continually or in a few discrete steps, while the beam current decreases, so as to keep the synchrotron radiation power at or below a certain limiting value. In this way, both peak and integrated luminosity of the FCC-hh are increased, compared with operation at a fixed beam energy. The FCC-hh detectors, and in particular the physics event analysis, need to be prepared for this novel mode of operation. This article presents two example running scenarios for synchrotron radiation leveling at the FCC-hh. While not greatly reducing the integrated luminosity at highest collision energy, synchrotron-radiation leveling can significantly increase the number of events for key processes already occurring at lower energy. As an example, we show that it raises the number of di-Higgs production events by 60% or more.

In this paper, our main goal is to define the class of weakly Demi Dunford-Pettis applications. We also study their relationship with the classes of weakly Dunford-Pettis and Demi Dunford-Pettis operators, including a condition where these operators coincide with Demi Dunford-Pettis and Demicompacts. In the last section, we study some of the behavior of this class in the Banach Lattice environment.

We present a Bianchi-Calo type construction method for Bryant type linear Weingarten surfaces in hyperbolic space.

In this work, we investigate positive recurrent Lévy diffusions driven by appropriately scaled Brownian motion and $α$-stable process (with $1<α<2$) in the small noise regime. Supposing that in the vanishing noise limit, our Lévy diffusion approaches a deterministic system with a unique asymptotically stable fixed point, we show that the limiting behavior of the one-dimensional marginal distribution at large times is dictated by the optimal value of a deterministic control problem, just as in the classical case of diffusions driven by small variance Brownian motion. In our case, the control is allowed to have two parts: continuous control and impulse control.

Resolving the mean-squared displacement (MSD) and velocity autocorrelation function (VACF) of interacting Brownian particles remains a central challenge in simulations of soft-matter systems, especially at low densities where particle-particle interactions are sparse and signals are dominated by thermal noise. A recently proposed noise-cancellation (NC) algorithm [Mandal et al. Phys. Rev. Lett. 123, 168001 (2019)] addresses this by decomposing particle trajectories into two components: free Brownian motion and interaction-induced displacements. The NC approximation enhances signal clarity by neglecting cross-correlations between the total particle displacements and the extracted interaction-induced contributions of the trajectories - an assumption that has so far lacked rigorous theoretical justification. In this work, we establish an exact theoretical relation between the VACF, the force autocorrelation function (FACF) characterizing the interaction-induced contributions, and these cross-correlations, which is valid for Brownian systems. We show that in thermal equilibrium, the cross-correlations vanish for Brownian systems because the VACF is strictly proportional to the negative FACF, which establishes the NC algorithm as an exact method. In contrast, for Brownian nonequilibrium systems, the cross-correlations remain finite, providing a direct fingerprint of nonequilibrium physics in such systems and a criterion to distinguish equilibrium from nonequilibrium states. Here, suitable corrections must be applied for the NC method to remain accurate. Our results expand the scope of the NC algorithm to a broad range of soft-matter systems in and out of equilibrium, where it has the potential to strongly enhance the resolution of VACF data obtained through simulations in future studies.

We present a broadband spectral analysis of the black hole X-ray binary GX 339-4 during its 2021 outburst, covering both hard and soft spectral states. Using simultaneous observations from NuSTAR, NICER, and Insight-HXMT, we investigate the evolution of the accretion disk with a focus on the disk normalization derived from the diskbb component, which serves as a proxy for the apparent inner disk radius. In the standard single Comptonization model, the disk normalization in the hard state is more than an order of magnitude lower than in the soft state ($\sim$0.3$\times$10$^3$ vs. $\sim$3.0$\times$10$^3$). This result contradicts the widely accepted view that the disk radius is smaller in the soft state than in the hard state. By incorporating an additional warm Comptonization component, the disk normalization in the hard state increases to values ($\gtrsim 10^4$) exceeding those in the soft state ($\sim 10^3$), yielding results consistent with a physically truncated, cooler accretion disk. The results of this work support the presence of a dual-corona geometry in the hard state, comprising both a hot, optically thin corona and a warm, optically thick corona, while the soft state spectrum is well described by a single hot Comptonization component alone. Our findings emphasize the importance of including a warm corona in hard-state spectra, as it leads to a more physically consistent picture of the accretion geometry across spectral states.

We show that the consistency of $\mathrm{ZF} + \mathrm{AD}_{\mathbb{R}} + ``Θ$ is measurable$"$ implies the consistency of $\mathrm{ZF} +``Θ$ is the least strongly regular cardinal and the least measurable cardinal$"$ + $``$all uncountable cardinals below $Θ$ are of countable cofinality$"$.

Neutron Resonance Transmission Analysis (NRTA) was explored as an arms control verification approach to support potential future nuclear weapon limiting treaties. A compact and portable neutron Time of Flight (ToF) system was developed to enable proof-of-concept NRTA measurements of special nuclear material (SNM). Using a short 2-meter flight path, the NRT system is sensitive to cross-section resonances of isotopes such as 235U, 238U, 239Pu and 240Pu between 1-100 eV incident neutron energies due to their physical nuclear structure. The detected neutron ToF spectrum exhibits transmission dips at resonance energies that are characteristic of SNM isotopic composition in the inspected item. The proof-of-concept measurements of Highly Enriched Uranium (HEU), Depleted Uranium (DU), and Reactor Grade Plutonium (RGPu) confirmed the characteristic resonance features within two hours of data collection time. Analysis via the REFIT resonance fitting tool accurately predicted the 235U enrichment and Pu isotopic composition within 5% and 6% of the known values, respectively.

Mass measurements of nuclei can identify structurally-driven trends in binding energy across isotopic chains, and can also isolate specific nucleon-nucleon interactions, such as the $δV_{\mathrm{pn}}$ interaction of the last two valence protons with the last two valence neutrons. Below $^{208}$Pb, investigation of the local binding energy and $δV_{\mathrm{pn}}$ systematics can facilitate a better understanding of the behaviour of the proton-neutron interaction in the 'hole-hole' regime (where valence interactions can be modelled in hole-space rather than particle-space) and provide insight on the potential onset of a prolate-to-oblate shape transition. However, measurement of the necessary nuclei has been exceptionally challenging. Here we present six first-time measurements of neutron-rich ytterbium, using advanced rare isotope production and mass spectrometry techniques, leading to the identification of an anomalously strong proton-neutron interaction in the 'hole-hole' quadrant below $^{208}$Pb. The scale of this interaction, at $^{186}$Hf, is comparable to that of similar signals at doubly-magic nuclei and shape transitions. The experimental results are compared with contemporary mean-field model predictions, that do not accurately reproduce the anomaly. The results are also used to benchmark predictions from several models, to facilitate more accurate descriptions towards a key r-process waiting point at $N = 126$.

We study the long-time behavior of a passive scalar transported by an incompressible flow in the presence of smooth, deterministic forcing. For a specific spatially Lipschitz and time-periodic velocity field, we prove that all sufficiently smooth initial data is attracted to a limiting solution that satisfies a cumulative form of Batchelor's law. To our knowledge, this provides the first example for which a version of Batchelor's law can be established with deterministic forcing.

A numerical simulation using the chaotic Dynamics of intermittency at a finite size Z(3) spin system in a 3D lattice reveals: (a) the existence of a second order phase transition with a zone hysteresis characterized from resonances phenomena (b) An hybrid appearance of mean-field universality class and 3D Ising model universality class , all these inside the zone hysteresis (c) a weak first order phase transition through a tricritical crossover. So, a complicated behavior in Z(3) symmetry exists.

We develop a non-extensive thermodynamic formalism for the one-sided shift on a finite alphabet, inspired by Tsallis' generalization of Boltzmann entropy in statistical physics. We introduce notions of $q$-entropy, $q$-pressure, and $q$-transfer operators which extend the classical thermodynamic formalism when $q=1$. We prove a Bowen-type relation linking the $q$-pressure with a $(2-q)$-Ruelle transfer operator and show that $q$-equilibrium states correspond to classical equilibrium states for a related potential. We establish the existence and uniqueness of $q$-equilibrium states for Lipschitz potentials, prove the differentiability of the $q$-pressure, and obtain variational principles for both the $q$-pressure and a related asymptotic pressure. Finally, we study cohomological equations associated with $(2-q)$-transfer operators and prove the differentiable dependence of their solutions on the potential, yielding an alternative construction of eigenfunctions for classical Ruelle operators.

The article presents weighted adjacency spectrum of complete multipartite graphs, characterize its families with three distinct eigenvalues and identifies integral matrices. Also, we observe that for almost all weighted matrices, the energy and the spectral radius of a complete graph decreases upon edge deletion, thereby correcting and refining earlier published results in [Bilal and Munir, Int. J. Quantum Chem. (2024)]. Furthermore, we give counter examples related to $ISI$ energy decrease of regular tripartite graph by edge deletion and give its correct $ISI$ spectrum and $ISI$ energy and settle an open problem related to $ISI$ energy change of the multipartite graph. Also, we calculate the weighted adjacency spectrum of crown multipartite graph and discuss its integral spectral weighted spectrum.