Results 61 to 70 of about 530,171 (149)
On the automorphisms of the power semigroups of a numerical semigroup
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract If H$H$ is a numerical semigroup (i.e., a cofinite subset of the non‐negative integers closed under addition), then the collection of all non‐empty subsets of H$H$ forms a semigroup P(H)$\mathcal {P}(H)$ under the sumset operation induced by addition in H$H$.
Salvatore Tringali, Kerou Wen
wiley +1 more source
Non‐Central Wishart Random Matrices in Structural Dynamics: A Modal‐Basis Approach
International Journal for Numerical Methods in Engineering, Volume 127, Issue 20, 30 October 2026.ABSTRACT This article develops a non‐parametric stochastic computational model for linear structural dynamics based on a reduced non‐central Wishart (NCW) random matrix formulation. The objective is to represent uncertainty in the mass and stiffness matrices while preserving the matrix properties required for modal and frequency‐domain analysis ...
Alan Das Mannoosseril +2 more
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Stochastic Gradient Descent in High Dimensions for Multi‐Spiked Tensor PCA
Communications on Pure and Applied Mathematics, Volume 79, Issue 10, Page 2291-2369, October 2026.ABSTRACT We study the high‐dimensional dynamics of online stochastic gradient descent (SGD) for the multi‐spiked tensor model. This multi‐index model arises from the tensor principal component analysis (PCA) problem with multiple spikes, where the goal is to estimate the unknown signal vectors within the N$N$‐dimensional unit sphere through maximum ...
Gérard Ben Arous +2 more
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Meander graphs and Frobenius Seaweed Lie algebras
, 2010 The index of a seaweed Lie algebra can be computed from its associated meander graph. We examine this graph in several ways with a goal of determining families of Frobenius (index zero) seaweed algebras. Our analysis gives two new families of Frobenius seaweed algebras as well as elementary proofs of known families of such Lie algebras.
Magnant, Colton +2 more
openaire +3 more sources
Large Covariance Matrix Estimation by Penalized Log‐Det Heuristics
Statistical Analysis and Data Mining: An ASA Data Science Journal, Volume 19, Issue 5, October 2026.ABSTRACT We study covariance estimation in high‐dimensional approximate factor models with a sparse residual covariance. The estimator combines a log‐det loss with nuclear‐norm and off‐diagonal ℓ1$$ {\mathrm{\ell}}_1 $$ penalties on a sample‐normalized covariance scale.
Enrico Bernardi, Matteo Farnè
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Gibbons–Tsarev Type Systems and Eventual Identities
Studies in Applied Mathematics, Volume 157, Issue 4, October 2026.ABSTRACT We show that non‐diagonalizable reductions of the dKP equation associated with regular non‐semisimple F$F$‐manifolds cannot exist. The proof is based on the derivation and study of a generalized Gibbons–Tsarev system (gGT system) in the non‐semisimple/non‐diagonalizable setting.
Alessandro Arsie +3 more
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On the geometry of WDVV equations and their Hamiltonian formalism in arbitrary dimension
Journal of the London Mathematical Society, Volume 114, Issue 4, October 2026.Abstract It is known that in low dimensions Witten–Dijkgraaf–Verlinde–Verlinde (WDVV) equations can be rewritten as commuting quasilinear bi‐Hamiltonian systems. We extend some of these results to arbitrary dimension N$N$ and arbitrary scalar product η$\eta$.
S. Opanasenko, R. Vitolo
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bk$b^k$‐Algebroids and the variety of foliation jets
Journal of the London Mathematical Society, Volume 114, Issue 4, October 2026.Abstract We introduce and classify singular foliations of bk+1$b^{k+1}$‐type, which formalize the properties of vector fields that are tangent to a submanifold W⊂M$W \subset M$ to order k$k$. When W$W$ is a hypersurface, these structures are Lie algebroids generalizing the bk+1$b^{k+1}$‐tangent bundles introduced by Scott.
Francis Bischoff +2 more
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Invariants of automorphic lie algebras [PDF]
Automorphic Lie Algebras arise in the context of reduction groups introduced in the late 1970s [35] in the field of integrable systems. They are subalgebras of Lie algebras over a ring of rational functions, denied by invariance under the action of a ...
Knibbeler, Vincent
core
Abelian number fields with frobenian conditions
Mathematika, Volume 72, Issue 4, October 2026.Abstract We study the distribution of abelian number fields with frobenian conditions imposed on the conductor. In particular, we find an asymptotic for the number of abelian field extensions of a number field k$k$ whose conductor is the sum of two squares. We also discuss an application of the Brauer group of stacks to quadratic number fields.
Julie Tavernier
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