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Related papers: Low eigenvalues and one-dimensional collapse

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We give a new lower bound for the first gap $\lambda_2 - \lambda_1$ of the Dirichlet eigenvalues of the Schr{\"o}dinger operator on a bounded convex domain $\Omega$ in R$^n$ or S$^n$ and greatly sharpens the previous estimates. The new…

Differential Geometry · Mathematics 2007-05-23 Jun Ling

In this paper we establish a gap theorem for the complex geometry of smoothly bounded convex domains which informally says that if the complex geometry near the boundary is close to the complex geometry of the unit ball, then the domain…

Complex Variables · Mathematics 2017-06-23 Andrew Zimmer

Given the Laplacian on a planar, convex domain with piecewise linear boundary subject to mixed Dirichlet-Neumann boundary conditions, we provide a sufficient condition for its lowest eigenvalue to dominate the lowest eigenvalue of the…

Spectral Theory · Mathematics 2017-10-03 Jonathan Rohleder

Concerning the Laplace operator with homogeneous Dirichlet boundary conditions, the classical notion of isospectrality assumes that two domains are related when they give rise to the same spectrum. In two dimensions, non isometric,…

Numerical Analysis · Mathematics 2018-03-30 Lorella Fatone , Daniele Funaro

We add a divergence-free drift with increasing magnitude to the fractional Laplacian on a bounded smooth domain, and discuss the behavior of the principal eigenvalue for the Dirichlet problem. The eigenvalue remains bounded if and only if…

Analysis of PDEs · Mathematics 2013-09-26 Krzysztof Bogdan , Tomasz Komorowski

We address the problem of splitting of eigenvalues of the Neumann Laplacian under singular domain perturbations. We consider a domain perturbed by the excision of a small spherical hole shrinking to an interior point. Our main result…

Analysis of PDEs · Mathematics 2026-01-21 Veronica Felli , Lorenzo Liverani , Roberto Ognibene

The Dirichlet eigenvalues of the Laplacian on a triangle that collapses into a line segment diverge to infinity. In this paper, to track the behavior of the eigenvalues during the collapsing process of a triangle, we establish a…

Spectral Theory · Mathematics 2025-04-01 Ryoki Endo , Xuefeng Liu

We show that, for horoconvex domains in the hyperbolic space, the product of their fundamental gap with the square of their diameter has no positive lower bound. The result follows from the study of the fundamental gap of geodesic balls as…

Differential Geometry · Mathematics 2021-01-26 Xuan Hien Nguyen , Alina Stancu , Guofang Wei

In their celebrated work, B. Andrews and J. Clutterbuck proved the fundamental gap (the difference between the first two eigenvalues) conjecture for convex domains in the Euclidean space and conjectured similar results holds for spaces with…

Differential Geometry · Mathematics 2017-03-16 Shoo Seto , Lili Wang , Guofang Wei

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

A connection between the semigroup of the Cauchy process killed upon exiting a domain $D$ and a mixed boundary value problem for the Laplacian in one dimension higher known as the "mixed Steklov problem," was established in a previous paper…

Probability · Mathematics 2007-05-23 Rodrigo Banuelos , Tadeusz Kulczycki

On a convex bounded Euclidean domain, the ground state for the Laplacian with Neumann boundary conditions is a constant, while the Dirichlet ground state is log-concave. The Robin eigenvalue problem can be considered as interpolating…

Analysis of PDEs · Mathematics 2018-02-21 Ben Andrews , Julie Clutterbuck , Daniel Hauer

In Euclidean and Hyperbolic space, and the hemisphere in $S^n$, geodesic balls maximize the gap $\lambda_2 - \lambda_1$ of Dirichlet eigenvalues, amoung domains with fixed $\lambda_1$. We prove an upper bound on $\lambda_2 - \lambda_1$ for…

Differential Geometry · Mathematics 2016-12-26 Nick Edelen

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

We establish geometric lower bounds for the smallest positive eigenvalue of the Hodge Laplacian in the class of non-convex domains given by Euclidean annular regions with a convex outer boundary and a spherical inner boundary. These bounds…

Differential Geometry · Mathematics 2026-04-21 Tirumala Chakradhar , Pierre Nicolle-Guerini

In this paper, motivated by study on universal inequalities for eigenvalues of the Dirichlet Laplacian, we prove some new inequalities for eigenvalues of the Dirichlet Laplacian on the hyperbolic space. In particular, we verify Cheng's…

Analysis of PDEs · Mathematics 2026-04-23 Yong Luo

The eigenvalue problem for the Laplacian on bounded, planar, convex domains with mixed boundary conditions is considered, where a Dirichlet boundary condition is imposed on a part of the boundary and a Neumann boundary condition on its…

Spectral Theory · Mathematics 2023-01-26 Nausica Aldeghi , Jonathan Rohleder

We study the Dirichlet eigenvalues of the Laplacian on a convex domain in $\mathbb{R}^n$, with $n\geq 2$. In particular, we generalize and improve upper bounds for the Riesz means of order $\sigma\geq 3/2$ established in an article by…

Spectral Theory · Mathematics 2017-04-05 Simon Larson

Let $(M,g)$ be a compact $n$-dimensional Riemannian manifold with nonempty boundary and $n\geq 2$. Assume that ${\mathrm{Ric}(M)\ge (n-1)K}$ for some ${K>0}$ and that $\partial M$ has nonnegative mean curvature with respect to the outward…

Differential Geometry · Mathematics 2025-12-29 Thomas Schürmann

We establish two universal inequalities for Dirichlet eigenvalues of the Laplacian on a Euclidean convex domain.

Spectral Theory · Mathematics 2026-04-14 Kei Funano