English

Exceptional points and double poles of the S matrix

Quantum Physics 2016-09-08 v1

Abstract

Exceptional points and double poles of the S matrix are both characterized by the coalescence of a pair of eigenvalues. In the first case, the coalescence causes a defect of the Hilbert space. In the second case, this is not so as shown in prevoius papers. Mathematically, the reason for this difference is the bi-orthogonality of the eigenfunctions of a non-Hermitian operator that is ignored in the first case. The consequences for the topological structure of the Hilbert space are studied and compared with existing experimental data.

Keywords

Cite

@article{arxiv.quant-ph/0211197,
  title  = {Exceptional points and double poles of the S matrix},
  author = {I. Rotter},
  journal= {arXiv preprint arXiv:quant-ph/0211197},
  year   = {2016}
}

Comments

9 pages, no figures

R2 v1 2026-07-22T19:37:24.123Z