Results 81 to 90 of about 1,586 (206)

Context‐free graphs and their transition groups

Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.
Abstract Starting from context‐free inverse graphs, we introduce a new class of groups and study their structural properties. We establish closure properties, show that their coword problems are context‐free, analyze torsion elements, and realize them as subgroups of the asynchronous rational group.
Daniele D'Angeli, Francesco Matucci, Davide Perego, Emanuele Rodaro   +3 more
wiley   +1 more source

Deep Spatially Varying Coefficient Model for Interpolation of Non‐Stationary Meteorological Data

Environmetrics, Volume 37, Issue 6, September 2026.
ABSTRACT In spatial statistics, the spatially varying coefficient model (SVCM) is widely applied in the analysis and interpolation of non‐stationary spatial data. By incorporating spatially varying coefficients, the model can capture spatial heterogeneity and provide an attractive interpretation of response‐covariate associations.
Tong Wu, Nan Chen, Zhi‐Sheng Ye
wiley   +1 more source

Fractal–fractional model for analysis of tuberculosis infection using Ethiopia incidence data

Quantitative Biology, Volume 14, Issue 3, September 2026.
Abstract In this study, a fractional‐order SEIuITR $SE{I}_{u}ITR$ model was proposed to examine the transmission of tuberculosis (TB) in the community. The proposed model was rigorously examined for well‐posedness. The basic reproduction number was also derived, and the disease‐free equilibrium was obtained.
Kumama Regassa Cheneke, Fatmawati Fatmawati, Mustafa Bayram   +2 more
wiley   +1 more source

Do stable neural networks exist for classification problems? – A new view on stability in AI

European Journal of Applied Mathematics
In deep learning (DL), the instability phenomenon is widespread and well documented, and the most commonly used measure of stability is the Lipschitz constant.
David Liu, Anders Hansen
doaj   +1 more source

Surface subgroups for cocompact lattices of isometries of H2n$\mathbb {H}^{2n}$

Journal of Topology, Volume 19, Issue 3, September 2026.
Abstract We prove the existence of surface subgroups within any cocompact lattice Γ$\Gamma$ in SO(2n,1)$\mathrm{SO}(2n,1)$ for n⩾2$n\geqslant 2$. This result addresses the cases missing from the work of Hamenstädt in 2015, who constructed surface subgroups in cocompact lattices for all other rank‐1 simple Lie groups of noncompact type.
Jeremy Kahn, Zhenghao Rao
wiley   +1 more source

Invariant Measure and Universality of the 2D Yang–Mills Langevin Dynamic

Communications on Pure and Applied Mathematics, Volume 79, Issue 8, Page 1973-2102, August 2026.
ABSTRACT We prove that the Yang–Mills (YM) measure for the trivial principal bundle over the two‐dimensional torus, with any connected, compact structure group, is invariant for the associated renormalised Langevin dynamic. Our argument relies on a combination of regularity structures, lattice gauge‐fixing and Bourgain's method for invariant measures ...
Ilya Chevyrev, Hao Shen
wiley   +1 more source

Edge‐Length Preserving Embeddings of Graphs Between Normed Spaces

Journal of Graph Theory, Volume 112, Issue 4, Page 491-506, August 2026.
ABSTRACT The concept of graph embeddability, initially formalized by Belk and Connelly and later expanded by Sitharam and Willoughby, extends the question of embedding finite metric spaces into a given normed space. A finite simple graph G = ( V , E ) is said to be ( X , Y )‐embeddable if any set of induced edge lengths from an embedding of G into a ...
Sean Dewar, Eleftherios Kastis, Derek Kitson, William Sims   +3 more
wiley   +1 more source

Existence of solutions for discontinuous p(x)-Laplacian problems with critical exponents

Electronic Journal of Differential Equations, 2012
In this article, we study the existence of solutions to the problem $$displaylines{ -hbox{div}(|abla u|^{p(x)-2}abla u) =lambda |u|^{p^{*}(x)-2}u + f(u)quad x in Omega ,cr u = 0 quad x in partialOmega, }$$ where $Omega$ is a smooth bounded domain ...
Xudong Shang, Zhigang Wang
doaj  

Existence of Solution for Two Classes of Quasilinear Systems Defined on a Nonreflexive Orlicz–Sobolev Spaces

Mathematical Methods in the Applied Sciences, Volume 49, Issue 12, Page 13324-13360, August 2026.
ABSTRACT This paper proves the existence of nontrivial solution for two classes of quasilinear systems of the type −ΔΦ1u=Fu(x,u,v)+λRu(x,u,v)inΩ−ΔΦ2v=−Fv(x,u,v)−λRv(x,u,v)inΩu=v=0on∂Ω$$ \left\{\begin{array}{l}\hfill -{\Delta}_{\Phi_1}u={F}_u\left(x,u,v\right)+\lambda {R}_u\left(x,u,v\right)\kern0.1832424242424242em \mathrm{in}\kern0.3em \Omega ...
Lucas da Silva, Marco Souto
wiley   +1 more source

Shape Derivatives of the Eigenvalues of the de Rham Complex for Lipschitz Deformations and Variable Coefficients: Part II

Mathematical Methods in the Applied Sciences, Volume 49, Issue 12, Page 14244-14265, August 2026.
ABSTRACT In this second part of our series of papers, we develop an abstract framework suitable for de Rham complexes that depend on a parameter belonging to an arbitrary Banach space. Our primary focus is on spectral perturbation problems and the differentiability of eigenvalues with respect to perturbations of the involved parameters. As a byproduct,
Pier Domenico Lamberti, Dirk Pauly, Michele Zaccaron   +2 more
wiley   +1 more source