English

Hyperbolic triangles without embedded eigenvalues

Spectral Theory 2017-11-07 v2 Classical Analysis and ODEs Differential Geometry

Abstract

We consider the Neumann Laplacian acting on square-integrable functions on a triangle in the hyperbolic plane that has one cusp. We show that the generic such triangle has no eigenvalues embedded in its continuous spectrum. To prove this result we study the behavior of the real-analytic eigenvalue branches of a degenerating family of triangles. In particular, we use a careful analysis of spectral projections near the crossings of these eigenvalue branches with the eigenvalue branches of a model operator.

Keywords

Cite

@article{arxiv.1402.4533,
  title  = {Hyperbolic triangles without embedded eigenvalues},
  author = {Luc Hillairet and Chris Judge},
  journal= {arXiv preprint arXiv:1402.4533},
  year   = {2017}
}

Comments

65 pages, 4 figures, to appear in Annals of Mathematics http://annals.math.princeton.edu/articles/11599

R2 v1 2026-06-22T03:11:06.743Z