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arXiv · 2402.04164

A note on the persistence of multiplicity of eigenvalues of fractional Laplacian under perturbations

Marco Ghimenti·Anna Maria Micheletti·Angela Pistoia
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Abstract

We consider the eigenvalues problem for the the fractional Laplacian in a bounded domain Omega with Dirichlet boundary condition. A recent result by Fall, Ghimenti, Micheletti and Pistoia (CVPDE (2023)) states that under generic small perturbations of the coefficient of the equation or of the domain Omega all the eigenvalues are simple. In this paper we give a condition for which a perturbation of the coefficient or of the domain preserves the multiplicity of a given eigenvalue. Also, in the case of an eigenvalue of multiplicity 2 we prove that the set of perturbations of the coefficients which preserve the multiplicity is a smooth manifold of codimension $2$ in C^1(Omega).

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Marco Ghimenti, Anna Maria Micheletti, Angela Pistoia. 2024-02-06. A note on the persistence of multiplicity of eigenvalues of fractional Laplacian under perturbations. https://arxiv.org/abs/2402.04164

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