Results 11 to 20 of about 775 (185)
SPHARA--a generalized spatial Fourier analysis for multi-sensor systems with non-uniformly arranged sensors: application to EEG. [PDF]
PLoS ONE, 2015 Important requirements for the analysis of multichannel EEG data are efficient techniques for signal enhancement, signal decomposition, feature extraction, and dimensionality reduction.
Uwe Graichen +5 more
doaj +1 more source
The best approximation of closed operators by bounded operators in Hilbert spaces
Karpatsʹkì Matematičnì Publìkacìï, 2022 We solve the problem of the best approximation of closed operators by linear bounded operators in Hilbert spaces under assumption that the operator transforms orthogonal basis in Hilbert space into an orthogonal system.
V.F. Babenko +2 more
doaj +1 more source
Annales Universitatis Paedagogicae Cracoviensis: Studia Mathematica, 2016 We consider the eigenvalue problem for the p(x)-Laplace - Beltrami operator on the unit sphere. We prove an integro - differential inequality related to the smallest positive eigenvalue of this problem.
Damian Wiśniewski, Mariusz Bodzioch
doaj +1 more source
The Laplace-Beltrami operator in almost-Riemannian Geometry [PDF]
Annales de l'Institut Fourier, 2013 We study the Laplace-Beltrami operator of generalized Riemannian structures on orientable surfaces for which a local orthonormal frame is given by a pair of vector fields that can become collinear. Under the assumption that the structure is 2-step Lie bracket generating, we prove that the Laplace-Beltrami operator is essentially self ...
Boscain, Ugo and Laurent, Camille
openaire +2 more sources
A formula for complex zonal polynomials of second order
Revista de Matemática: Teoría y Aplicaciones, 2009 A formula for complex zonal polynomials of second order is derived by solving a particular partial differential equation. Keywords: Laplace-Beltrami operator, zonal polynomials, Hermitian matrix, Legendre’s differential equation.
Francisco J. Caro Lopera +2 more
doaj +1 more source
A Discrete Laplace–Beltrami Operator for Simplicial Surfaces [PDF]
Discrete & Computational Geometry, 2007 We define a discrete Laplace-Beltrami operator for simplicial surfaces. It depends only on the intrinsic geometry of the surface and its edge weights are positive. Our Laplace operator is similar to the well known finite-elements Laplacian (the so called ``cotan formula'') except that it is based on the intrinsic Delaunay triangulation of the ...
Alexander I. Bobenko, Boris Springborn
openaire +3 more sources
Nonlinear Choquard equations on hyperbolic space [PDF]
Opuscula Mathematica, 2022 In this paper, our purpose is to prove the existence results for the following nonlinear Choquard equation \[-\Delta_{\mathbb{B}^{N}}u=\int_{\mathbb{B}^N}\dfrac{|u(y)|^{p}}{|2\sinh\frac{\rho(T_y(x))}{2}|^\mu} dV_y \cdot |u|^{p-2}u +\lambda u\] on the ...
Haiyang He
doaj +1 more source
SpharaPy: A Python toolbox for spatial harmonic analysis of non-uniformly sampled data
SoftwareX, 2019 SpharaPy is a Python implementation of a new approach for spatial harmonic analysis (SPHARA). SPHARA extends the classical spatial Fourier analysis to non-uniformly positioned samples on arbitrary surfaces in R3.
Uwe Graichen +2 more
doaj +1 more source
Journal of Mathematics, 2021 In the present paper, we establish a Chen–Ricci inequality for a C-totally real warped product submanifold Mn of Sasakian space forms M2m+1ε. As Chen–Ricci inequality applications, we found the characterization of the base of the warped product Mn via ...
Fatemah Mofarreh +3 more
doaj +1 more source
Eigenfunctions of the Laplace-Beltrami operator on hyperboloids
Tamkang Journal of Mathematics, 2008 Eigenfunctions of the Laplace-Beltrami operator on a hyperboloid are studied in the spirit of the treatment of the spherical harmonics by Stein and Weiss. As a special case, a simple self-contained proof of Laplace’s integral for a Legendre function is obtained.
Prasad, Amritanshu, Vemuri, M. K.
openaire +3 more sources