English

Exceptional points of infinite order give a continuous spectrum

Mathematical Physics 2015-06-23 v1 High Energy Physics - Theory math.MP

Abstract

The statement in the title discussed earlier in association with the Pais-Uhlenbeck oscillator with equal frequencies is illustrated for an elementary matrix model. In the limit when the order of the exceptional point N tends to infinity, an infinity of nontrivial states that do not change their norm during evolution appear. These states have real energies lying in a continuous interval. The norm of the "precursors" of these states at large finite N is not conserved, but the characteristic time scale where this nonconservation shows up grows linearly with N.

Cite

@article{arxiv.1409.8450,
  title  = {Exceptional points of infinite order give a continuous spectrum},
  author = {A. V. Smilga},
  journal= {arXiv preprint arXiv:1409.8450},
  year   = {2015}
}

Comments

7 pages, 1 figure

R2 v1 2026-06-22T06:09:14.211Z