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Related papers: Numerical optimisation of Dirac eigenvalues

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We establish a sharp extrinsic lower bound for the first eigenvalue of the Dirac operator of an untrapped surface in initial data sets without apparent horizon in terms of the norm of its mean curvature vector. The equality case leads to…

Differential Geometry · Mathematics 2014-05-28 Simon Raulot

For a bounded domain $\Omega$ with a piecewise smooth boundary in an $n$-dimensional Euclidean space $\mathbf{R}^{n}$, we study eigenvalues of the Dirichlet eigenvalue problem of the Laplacian. First we give a general inequality for…

Differential Geometry · Mathematics 2011-06-09 Qing-Ming Cheng , Xuerong Qi

In this note, we prove lower and upper bounds for Dirac operators of submanifolds in certain ambient manifolds in terms of conformal and extrinsic quantities.

Differential Geometry · Mathematics 2018-10-18 Qun Chen , Linlin Sun

Using Weitzenb\"ock techniques on any compact Riemannian spin manifold we derive inequalities that involve a real parameter and join the eigenvalues of the Dirac operator with curvature terms. The discussion of these inequalities yields…

Differential Geometry · Mathematics 2009-11-10 K. -D. Kirchberg

This paper studies the problem of selecting a submatrix of a positive definite matrix in order to achieve a desired bound on the smallest eigenvalue of the submatrix. Maximizing this smallest eigenvalue has applications to selecting input…

Systems and Control · Computer Science 2017-09-08 Andrew Clark , Qiqiang Hou , Linda Bushnell , Radha Poovendran

The aim of this paper is to study the existence of eigenvalues in the gap of the essential spectrum of the one-dimensional Dirac operator in the presence of a bounded potential. We employ a generalized variational principle to prove…

Spectral Theory · Mathematics 2025-03-24 Daniel Sánchez-Mendoza , Monika Winklmeier

We prove a lower estimate for the first eigenvalue of the Dirac operator on a compact locally reducible Riemannian spin manifold with positive scalar curvature. We determine also the universal covers of the manifolds on which the smallest…

Differential Geometry · Mathematics 2007-05-23 Bogdan Alexandrov

Eigenmaps are important in analysis, geometry, and machine learning, especially in nonlinear dimension reduction. Approximation of the eigenmaps of a Laplace operator depends crucially on the scaling parameter $\epsilon$. If $\epsilon$ is…

This paper is concerned with the Dirichlet eigenvalue problem for Laplace operator in a bounded domain with periodic perforation in the case of small volume. We obtain the optimal quantitative error estimates independent of the spectral…

Analysis of PDEs · Mathematics 2024-08-27 Zhongwei Shen , Jinping Zhuge

We consider the Laplace operator in the exterior of a compact set in the plane, subject to Robin boundary conditions. If the boundary coupling is sufficiently negative, there are at least two discrete eigenvalues below the essential…

Optimization and Control · Mathematics 2025-02-05 David Krejcirik , Vladimir Lotoreichik

We investigate how the lowest eigenvalue of a magnetic Laplacian depends on the geometry of a planar domain with a disk shaped hole, where the magnetic field is generated by a singular flux. Under Dirichlet boundary conditions on the inner…

Analysis of PDEs · Mathematics 2025-05-14 Mrityunjoy Ghosh , Ayman Kachmar

It is proved that the minimal Dirichlet eigenvalue of the Laplacian in an annulus is a monotonically decreasing function of the displacement of the center of the smaller disc. The maximal value of the minimal eigenvalue is attained when the…

Mathematical Physics · Physics 2007-05-23 A. G. Ramm , P. N. Shivakumar

We prove various estimates for the first eigenvalue of the magnetic Dirichlet Laplacian on a bounded domain in two dimensions. When the magnetic field is constant, we give lower and upper bounds in terms of geometric quantities of the…

Spectral Theory · Mathematics 2015-01-23 Tomas Ekholm , Hynek Kovarik , Fabian Portmann

It has been conjectured by P\'{o}lya and Szeg\"{o} seventy years ago that the planar set which minimizes the first eigenvalue of the Dirichlet-Laplace operator among polygons with $n$ sides and fixed area is the regular polygon. Despite its…

Optimization and Control · Mathematics 2022-03-31 Beniamin Bogosel , Dorin Bucur

Maximization and minimization problems of the principle eigenvalue for divergence form second order elliptic operators with the Dirichlet boundary condition are considered. The principal eigen map of such elliptic operators is introduced…

Optimization and Control · Mathematics 2019-08-28 Hongwei Lou , Jiongmin Yong

In K\"ahler-Einstein case of positive scalar curvature and even complex dimension, an improved lower bound for the first eigenvalue of the Dirac operator is given. It is shown by a general construction that there are manifolds for which…

Differential Geometry · Mathematics 2009-12-09 K. -D. Kirchberg

We study the magnetic Laplacian in a two-dimensional exterior domain with Neumann boundary condition and uniform magnetic field. For the exterior of the disk we establish accurate asymptotics of the low-lying eigenvalues in the weak…

Spectral Theory · Mathematics 2024-05-29 Ayman Kachmar , Vladimir Lotoreichik , Mikael Sundqvist

We discuss a novel strategy for computing the eigenvalues and eigenfunctions of the relativistic Dirac operator with a radially symmetric potential. The virtues of this strategy lie on the fact that it avoids completely the phenomenon of…

Analysis of PDEs · Mathematics 2019-02-20 Lyonell Boulton , Nabile Boussaid

This paper is devoted to a general min-max characterization of the eigenvalues in a gap of the essential spectrum of a self-adjoint unbounded operator. We prove an abstract theorem, then we apply it to the case of Dirac operators with a…

Spectral Theory · Mathematics 2022-06-14 Jean Dolbeault , Maria J. Esteban , Eric Séré

This paper deals with the numerical optimization of the first three eigenvalues of the Laplace-Beltrami operator of domain in the Euclidean sphere in $\mathbb{R}^3$ with Neumann boundary conditions. We address two approaches : the first one…

Analysis of PDEs · Mathematics 2023-03-23 Eloi Martinet