English

The Robin problem on rectangles

Spectral Theory 2021-11-24 v2 Analysis of PDEs Number Theory

Abstract

We study the statistics and the arithmetic properties of the Robin spectrum of a rectangle. A number of results are obtained for the multiplicities in the spectrum, depending on the Diophantine nature of the aspect ratio. In particular, it is shown that for the square, unlike the case of Neumann eigenvalues where there are unbounded multiplicities of arithmetic origin, there are no multiplicities in the Robin spectrum for sufficiently small (but nonzero) Robin parameter except a systematic symmetry. In addition, uniform lower and upper bounds are established for the Robin-Neumann gaps in terms of their limiting mean spacing. Finally, that the pair correlation function of the Robin spectrum on a Diophantine rectangle is shown to be Poissonian.

Keywords

Cite

@article{arxiv.2103.15129,
  title  = {The Robin problem on rectangles},
  author = {Zeév Rudnick and Igor Wigman},
  journal= {arXiv preprint arXiv:2103.15129},
  year   = {2021}
}

Comments

3 figures. Arguments in section 2 simplified thanks to a referee. Accepted for publication in the Journal of Mathematical Physics, special collection of papers honoring Freeman Dyson

R2 v1 2026-06-24T00:37:26.625Z