Counterexamples to Ashbaugh's higher-index PPW conjecture for Dirichlet Laplacian eigenvalue ratios, with exact-arithmetic verification.
mathematics partial-differential-equations counterexample spectral-geometry bessel-functions dirichlet-laplacian eigenvalue-inequalities eigenvalue-ratios ppw-inequality payne-polya-weinberger ashbaugh-conjecture
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Updated
Aug 14, 2026 - TeX