Results 71 to 80 of about 2,836 (190)

Riemannian transfer learning based on log-Euclidean metric for EEG classification

Frontiers in Neuroscience
IntroductionBrain computer interfaces (BCI), which establish a direct interaction between the brain and the external device bypassing peripheral nerves, is one of the hot research areas.
Fanbo Zhuo, Fanbo Zhuo, Fanbo Zhuo, Xiaocheng Zhang, Xiaocheng Zhang, Xiaocheng Zhang, Fengzhen Tang, Fengzhen Tang, Yaobo Yu, Yaobo Yu, Lianqing Liu, Lianqing Liu   +11 more
doaj   +1 more source

Index of Quasiconformally Symmetric Semi-Riemannian Manifolds

International Journal of Mathematics and Mathematical Sciences, 2012
We find the index of ∇˜-quasiconformally symmetric and ∇˜-concircularly symmetric semi-Riemannian manifolds, where ∇˜ is metric connection.
Mukut Mani Tripathi, Punam Gupta, Jeong-Sik Kim   +2 more
doaj   +1 more source

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, Cédric Gerbelot, Vanessa Piccolo   +2 more
wiley   +1 more source

Metric completions, the Heine-Borel property, and approachability

Open Mathematics, 2020
We show that the metric universal cover of a plane with a puncture yields an example of a nonstandard hull properly containing the metric completion of a metric space.
Kanovei Vladimir, Katz Mikhail G., Nowik Tahl   +2 more
doaj   +1 more source

Hearing the Serre Invariant of a Compact p‐Adic Analytic Manifold

Mathematische Nachrichten, Volume 299, Issue 10, Page 3126-3138, October 2026.
ABSTRACT Using a previous novel way of defining kernel functions for Laplacian integral operators on a compact p$p$‐adic analytic manifold X$X$, one such operator Δ0s$\Delta _0^s$ with s∈R$s\in \mathbb {R}$ is applied to hearing the Serre invariant i(X)$i(X)$ by showing that a wavelet eigenvalue (with the wavelet having small support) is always ...
Patrick Erik Bradley, Ángel Morán Ledezma   +1 more
wiley   +1 more source

Estimates of the Laplacian Spectrum and Bounds of Topological Invariants for Riemannian Manifolds with Boundary

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2019
We set out to obtain estimates of the Laplacian Spectrum of Riemannian manifolds with non-empty boundary. This was achieved using standard doubled manifold techniques. In simple terms, we pasted two copies of the same manifold along their common boundary
Sabatini Luca
doaj   +1 more source

A Randomized Algorithm for Simultaneously Diagonalizing Symmetric Matrices by Congruence

Numerical Linear Algebra with Applications, Volume 33, Issue 5, October 2026.
ABSTRACT A family of symmetric matrices A1,…,Ad$$ {A}_1,\dots, {A}_d $$ is simultaneously diagonalizable by congruence (SDC), also called nonorthogonal joint diagonalization, if there is an invertible matrix X$$ X $$ such that every XTAkX$$ {X}^T{A}_kX $$ is diagonal. In this work, a novel randomized SDC (RSDC) algorithm is proposed that reduces SDC to
Haoze He, Daniel Kressner
wiley   +1 more source

Topological and geometric rigidity of nonnegatively curved submanifolds

Bulletin of the London Mathematical Society, Volume 58, Issue 10, October 2026.
Abstract We investigate the topology and geometry of compact submanifolds in space forms of nonnegative curvature satisfying a lower bound on the sectional curvature that depends only on the length of the mean curvature vector of the immersion. We show that this condition imposes strong constraints on either the topology or geometry of the submanifold.
Theodoros Vlachos
wiley   +1 more source

Ricci Bi-Conformal and m-Modified Conformal Vector Fields: A Study With Respect to the Riemannian Extension Metric

Journal of Mathematics
This article explores the necessary and sufficient conditions for a vector field on the cotangent bundle of a Riemannian manifold to qualify as an m− modified conformal vector field or a Ricci bi-conformal vector field.
Lokman Bilen, Aydin Gezer, Cagri Karaman
doaj   +1 more source

Integrable Equations and Their Evolutions Based on Intrinsic Geometry of Riemann Spaces

International Journal of Mathematics and Mathematical Sciences, 2009
The intrinsic geometry of surfaces and Riemannian spaces will be investigated. It is shown that many nonlinear partial differential equations with physical applications and soliton solutions can be determined from the components of the relevant metric ...
Paul Bracken
doaj   +1 more source