On the torsion function for simply connected, open sets in $\R^2$

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Berg, Michiel van den, Bucur, Dorin
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909388383453184
author Berg, Michiel van den
Bucur, Dorin
author_facet Berg, Michiel van den
Bucur, Dorin
contents For an open set $\Om \subset \R^2$ let $λ(\Om)$ denote the bottom of the spectrum of the Dirichlet Laplacian acting in $L^2(\Om)$. Let $w_\Om$ be the torsion function for $\Om$, and let $\|.\|_p$ denote the $L^p$ norm. It is shown that there exist {$η_1>0,η_2>0$} such that { (i) $\|w_{\Om}\|_{\infty} λ(\Om)\ge 1+η_1$ for any non-empty, open, simply connected set $\Om\subset \R^2$ with $\lb(\Om) >0$, (ii) $\|w_{\Om}\|_1λ(\Om)\le {(1-η_2)}|\Om|$ for any non-empty, open, simply connected set $\Om\subset\R^2$ with finite measure $|\Om|$.
format Preprint
id arxiv_https___arxiv_org_abs_2402_14448
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On the torsion function for simply connected, open sets in $\R^2$
Berg, Michiel van den
Bucur, Dorin
Spectral Theory
Analysis of PDEs
For an open set $\Om \subset \R^2$ let $λ(\Om)$ denote the bottom of the spectrum of the Dirichlet Laplacian acting in $L^2(\Om)$. Let $w_\Om$ be the torsion function for $\Om$, and let $\|.\|_p$ denote the $L^p$ norm. It is shown that there exist {$η_1>0,η_2>0$} such that { (i) $\|w_{\Om}\|_{\infty} λ(\Om)\ge 1+η_1$ for any non-empty, open, simply connected set $\Om\subset \R^2$ with $\lb(\Om) >0$, (ii) $\|w_{\Om}\|_1λ(\Om)\le {(1-η_2)}|\Om|$ for any non-empty, open, simply connected set $\Om\subset\R^2$ with finite measure $|\Om|$.
title On the torsion function for simply connected, open sets in $\R^2$
topic Spectral Theory
Analysis of PDEs
url https://arxiv.org/abs/2402.14448