English
Related papers

Related papers: Constant potentials do not minimise the fundamenta…

200 papers

We show that for every negatively curved Hadamard manifold $X$ and every $D > 0$ there exists a convex domain $\Omega \subseteq X$ with diameter $D$ and a convex potential $V$ on $\Omega$ such that the fundamental gap of the operator…

Analysis of PDEs · Mathematics 2026-02-03 Frieder Jäckel

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

Motivated by an example of Shih, we compute the fundamental gap of a family of convex domains in the hyperbolic plane $\mathbb H^2$, showing that for some of them $\lambda_2 - \lambda_1 < \frac{3\pi^2}{D^2}$, where $D$ is the diameter of…

Differential Geometry · Mathematics 2019-12-02 Theodora Bourni , Julie Clutterbuck , Xuan Hien Nguyen , Alina Stancu , Guofang Wei , Valentina-Mira Wheeler

For the Laplace operator with Dirichlet boundary conditions on convex domains in $\mathbb H^n$, $n\geq 2$, we prove that the product of the fundamental gap with the square of the diameter can be arbitrarily small for domains of any…

Differential Geometry · Mathematics 2020-05-26 Theodora Bourni , Julie Clutterbuck , Xuan Hien Nguyen , Alina Stancu , Guofang Wei , Valentina-Mira Wheeler

We show that if $\Omega$ is an $m$-convex domain in $\mathbb R^n$ for some $2\le m<n$ whose boundary $b\Omega$ has a tubular neighbourhood of positive radius and is not $m$-flat near infinity, then $\Omega$ does not contain any immersed…

Differential Geometry · Mathematics 2024-11-01 Franc Forstneric

Let $\Omega \subset \mathbb{R}^n$ be a convex domain and let $f:\Omega \rightarrow \mathbb{R}$ be a positive, subharmonic function (i.e. $\Delta f \geq 0$). Then $$ \frac{1}{|\Omega|} \int_{\Omega}{f dx} \leq \frac{c_n}{ |\partial \Omega| }…

The fundamental gap of a domain is the difference between the first two eigenvalues of the Laplace operator. In a series of recent and celebrated works, it was shown that for convex domains in $\mathbb R^n$ and $\mathbb S^n$ with Dirichlet…

Differential Geometry · Mathematics 2023-06-12 Gabriel Khan , Malik Tuerkoen , Guofang Wei

In a Riemannian manifold a regular convex domain is said to be $\lambda$-convex if its normal curvature at each point is greater than or equal to $\lambda$. In a Hadamard manifold, the asymptotic behaviour of the quotient…

Differential Geometry · Mathematics 2013-03-21 J. Abardia , E. Gallego

We consider the Laplace-Beltrami operator with Dirichlet boundary conditions on convex domains in a Riemannian manifold $(M^n,g)$, and prove that the product of the fundamental gap with the square of the diameter can be arbitrarily small…

Differential Geometry · Mathematics 2022-11-14 Gabriel Khan , Xuan Hien Nguyen

We prove a sharp lower bound for the fundamental gap on convex domains in Gaussian spaces, the difference between the first two eigenvalues of the Ornstein-Uhlenbeck operator with Dirichlet boundary conditions. Our main result establishes…

Spectral Theory · Mathematics 2025-10-28 Jin Sun , Kui Wang

In this paper, we prove that the first eigenfunction of the Laplacian for a horo-convex domain $\Omega\subset\mathbb H^n$ is super log-concave when $\text{diam}(\Omega)$ is not large. Our result is optimal in the sense that there are…

Analysis of PDEs · Mathematics 2025-10-16 Guofang Wei , Ling Xiao

We prove the Fundamental Gap Conjecture, which states that the difference between the first two Dirichlet eigenvalues (the spectral gap) of a Schr\"odinger operator with convex potential and Dirichlet boundary data on a convex domain is…

Spectral Theory · Mathematics 2011-01-12 Ben Andrews , Julie Clutterbuck

We give a lower estimate of the gap of the first two eigenvalues of the Schrodinger operator in the case when the potential is strongly convex. In particular, if the Hessian of the potential is bounded from below by a positive constant, the…

Differential Geometry · Mathematics 2009-02-16 Shing-Tung Yau

For a non-empty compact set $E$ in a proper subdomain $\Omega$ of the complex plane, we denote the diameter of $E$ and the distance from $E$ to the boundary of $\Omega$ by $d(E)$ and $d(E,\partial\Omega),$ respectively. The quantity…

Complex Variables · Mathematics 2021-12-07 Oona Rainio , Toshiyuki Sugawa , Matti Vuorinen

Let N be a complete, simply-connected surface of constant curvature \kappa \leq 0. Moreover, suppose that \Omega and \tilde{\Omega} are strictly convex domains in N with the same area. We show that there exists an area-preserving…

Differential Geometry · Mathematics 2008-05-29 S. Brendle

In [SWW], S. Seto, L. Wang and G. Wei proved that the gap between the first two Dirichlet eigenvalues of a convex domain in the unit sphere is at least as large as that for an associated operator on an interval with the same diameter,…

Differential Geometry · Mathematics 2017-06-01 Chenxu He , Guofang Wei

A property of smooth convex domains $\Omega \subset \mathbb{R}^n$ is that if two points on the boundary $x, y \in \partial \Omega$ are close to each other, then their normal vectors $n(x), n(y)$ point roughly in the same direction and this…

Classical Analysis and ODEs · Mathematics 2022-11-04 Stefan Steinerberger

In this paper, we establish the Weinstock inequality for the first non-zero Steklov eigenvalue on star-shaped mean convex domains in hyperbolic space $\mathbb{H}^n$ for $n \geq 4$. In particular, when the domain is convex, our result gives…

Differential Geometry · Mathematics 2024-09-05 Pingxin Gu , Haizhong Li , Yao Wan

We consider the difference between the two lowest eigenvalues (the fundamental gap) of a Schr\"{o}dinger operator acting on a class of graphs. In particular, we derive tight bounds for the gap of Schr\"{o}dinger operators with convex…

Mathematical Physics · Physics 2014-06-02 Michael Jarret , Stephen P. Jordan

We show that there exists a universal constant C>0 such that the convex hull of any N points in the hyperbolic space H^n is of volume smaller than C N, and that for any dimension n there exists a constant C_n > 0 such that for any subset A…

Metric Geometry · Mathematics 2013-05-21 Itai Benjamini , Ronen Eldan
‹ Prev 1 2 3 10 Next ›