Accepted Paper
Inserted: 14 oct 2021
Last Updated: 28 mar 2022
Journal: Ann. Mat. Pura Appl.
Pages: 30
Year: 2022
Abstract:
We prove that the first eigenvalue of the fractional Dirichlet-Laplacian of order $s$ on a simply connected set of the plane can be bounded from below in terms of its inradius only. This is valid for $1/2<s<1$ and we show that this condition is sharp, i.\,e. for $0<s\le 1/2$ such a lower bound is not possible. The constant appearing in the estimate has the correct asymptotic behaviour with respect to $s$, as it permits to recover a classical result by Makai and Hayman in the limit $s\nearrow 1$. The paper is as self-contained as possible.
Keywords: Poincare inequality, fractional Laplacian, Inradius, simply connected sets, Cheeger inequality
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