Abstract
The distance between the second and first eigenvalues for the Dirichlet Laplacian of a domain is called its (spectral) gap. We show that the gap of a convex planar domain D symmetric about both the x and y axes is no smaller than the gap of an oriented rectangle which contains D.
Citation
Burgess Davis. "On the spectral gap for fixed membranes." Ark. Mat. 39 (1) 65 - 74, March 2001. https://doi.org/10.1007/BF02388791
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