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Related papers: Sharp bounds for eigenvalues of triangles

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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

Lower bounds estimates are proved for the first eigenvalue for the Dirichlet Laplacian on arbitrary triangles using various symmetrization techniques. These results can viewed as a generalization of P\'olya's isoperimetric bounds. It is…

Spectral Theory · Mathematics 2008-07-17 Bartłomiej Siudeja

Sharp upper bounds for the first eigenvalue of the Laplacian on a surface of a fixed area are known only in genera zero and one. We investigate the genus two case and conjecture that the first eigenvalue is maximized on a singular surface…

Spectral Theory · Mathematics 2007-05-23 D. Jakobson , M. Levitin , N. Nadirashvili , N. Nigam , I. Polterovich

In this paper we look for the domains minimizing the h-th eigenvalue of the Dirichlet-Laplacian $\lambda$ h with a constraint on the diameter. Existence of an optimal domain is easily obtained, and is attained at a constant width body. In…

Analysis of PDEs · Mathematics 2018-01-08 B Bogosel , A Henrot , I Lucardesi

For any compact riemannian surface of genus three $(\Sigma,ds^2)$ Yang and Yau proved that the product of the first eigenvalue of the Laplacian $\lambda_1(ds^2)$ and the area $Area(ds^2)$ is bounded above by $24\pi$. In this paper we…

Differential Geometry · Mathematics 2021-05-06 Antonio Ros

This paper investigates the first Dirichlet eigenvalue for the $p$-Laplacian in Riemannian manifolds. Firstly, we establish a lower bound for this eigenvalue under the condition that the domain includes a specific function which fulfills…

Differential Geometry · Mathematics 2026-02-05 Xiaoshang Jin

In this paper, we establish a sharp lower bound for the first Dirichlet eigenvalue of the $p$-Laplacian on bounded domains of a complete, non-compact Riemannian manifold with non-negative Ricci curvature.

Differential Geometry · Mathematics 2026-01-21 Xiaoshang Jin , Zhiwei Lü

We prove a lower bound on the first eigenvalue of the fractional Dirichlet-Laplacian of order $s$ on planar open sets, in terms of their inradius and topology. The result is optimal, in many respects. In particular, we recover a classical…

Analysis of PDEs · Mathematics 2024-02-21 Francesca Bianchi , Lorenzo Brasco

We prove that, if $\Omega$ is an open bounded domain with smooth and connected boundary, for every $p \in (1, + \infty)$ the first Dirichlet eigenvalue of the normalized $p$-Laplacian is simple in the sense that two positive eigenfunctions…

Analysis of PDEs · Mathematics 2018-11-27 Graziano Crasta , Ilaria Fragalà , Bernd Kawohl

We prove sharp Dirichlet eigenvalue inequalities for planar triangles. We settle a conjecture of Laugesen and Siudeja by showing that the equilateral triangle uniquely minimizes a scale-invariant functional of the first Dirichlet…

Spectral Theory · Mathematics 2026-05-07 Ryoki Endo , Xuefeng Liu , Phanuel Mariano

Let $M$ be a closed hypersurface in a noncompact rank-1 symmetric space $(\bar{\mathbb{M}}, ds^2)$ with $-4 \leq K_{\bar{\mathbb{M}}} \leq -1,$ or in a complete, simply connected Riemannian manifold $\mathbb{M}$ such that $0 \leq…

Differential Geometry · Mathematics 2013-01-08 Binoy , G. Santhanam

We study the eigenvalue problem for the $p$-Laplacian on K\"ahler manifolds. Our first result is a lower bound for the first nonzero eigenvalue of the $p$-Laplacian on compact K\"ahler manifolds in terms of dimension, diameter, and lower…

Differential Geometry · Mathematics 2022-09-23 Kui Wang , Shaoheng Zhang

Motivated by relativistic materials, we develop a numerical scheme to support existing or state new conjectures in the spectral optimisation of eigenvalues of the Dirac operator, subject to infinite-mass boundary conditions. We study the…

Optimization and Control · Mathematics 2025-02-05 Pedro R. S. Antunes , Francisco Bento , David Krejcirik

We consider a Riemannian cylinder endowed with a closed potential 1-form A and study the magnetic Laplacian with magnetic Neumann boundary conditions associated with those data. We establish a sharp lower bound for the first eigenvalue and…

Differential Geometry · Mathematics 2017-09-28 Bruno Colbois , Alessandro Savo

We derive a lower bound to the spectral threshold of the Dirichlet Laplacian in tubular neighbourhoods of constant radius about complete surfaces. This lower bound is given by the lowest eigenvalue of a one-dimensional operator depending on…

Mathematical Physics · Physics 2017-09-08 Pedro Freitas , David Krejcirik

Among all triangles of given diameter, the equilateral triangle is shown to minimize the sum of the first $n$ eigenvalues of the Dirichlet Laplacian, for each $n \geq 1$. In addition, the first, second and third eigenvalues are each proved…

Spectral Theory · Mathematics 2010-08-10 Richard Laugesen , Bartlomiej Siudeja

We establish lower bound for the first nonzero eigenvalue of the Laplacian on a closed K\"ahler manifold in terms of dimension, diameter, and lower bounds of holomorphic sectional curvature and orthogonal Ricci curvature. On compact…

Differential Geometry · Mathematics 2020-10-27 Xiaolong Li , Kui Wang

We give an estimate on the lower bound of the first non-zero eigenvalue of the Laplacian for a closed Riemannian manifold with positive Ricci curvature in terms of the in-diameter and the lower bound of the Ricci curvature.

Differential Geometry · Mathematics 2007-05-23 Jun Ling

Given a Riemmanian manifold, we provide a new method to compute a sharp upper bound for the first eigenvalue of the Laplacian for the Dirichlet problem on a geodesic ball of radius less than the injectivity radius of the manifold. This…

Differential Geometry · Mathematics 2021-04-01 Vicent Gimeno , Erik Sarrion-Pedralva

A computer-assisted proof is proposed for the Laplacian eigenvalue minimization problems over triangular domains under diameter constraints. The proof utilizes recently developed guaranteed computation methods for both eigenvalues and…

Numerical Analysis · Mathematics 2022-09-30 Ryoki Endo , Xuefeng Liu
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