Characterizing all non-Hermitian degeneracies using algebraic approaches: Defectiveness and asymptotic behavior

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Sayyad, Sharareh, Starkov, Grigory A.
Format: Preprint
Publié: 2026
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866915946871914496
author Sayyad, Sharareh
Starkov, Grigory A.
author_facet Sayyad, Sharareh
Starkov, Grigory A.
contents The presence of degeneracies plays a crucial role in describing the behavior of non-Hermitian (NH) systems. In these systems, there are two key types of degeneracies: $n$-bolical degeneracies, which are analogous to Hermitian degeneracies, and various forms of exceptional points, each associated with different orders that correspond to sizes of the Jordan blocks. These types of degeneracies may coalesce at the same energy level, forming multi-block degeneracies. To understand how a multi-block degenerate NH system responds to perturbations, one should address how each types of involved degeneracies disperse. In this work, we systematically characterize the asymptotic behavior of all types of multi-block degeneracies in NH systems using a rigorous mathematical formulation. Through a range of examples, we demonstrate that our algebraic approach can facilitate the analysis of NH degeneracies in various settings relevant to experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2604_16140
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Characterizing all non-Hermitian degeneracies using algebraic approaches: Defectiveness and asymptotic behavior
Sayyad, Sharareh
Starkov, Grigory A.
Quantum Physics
Mathematical Physics
The presence of degeneracies plays a crucial role in describing the behavior of non-Hermitian (NH) systems. In these systems, there are two key types of degeneracies: $n$-bolical degeneracies, which are analogous to Hermitian degeneracies, and various forms of exceptional points, each associated with different orders that correspond to sizes of the Jordan blocks. These types of degeneracies may coalesce at the same energy level, forming multi-block degeneracies. To understand how a multi-block degenerate NH system responds to perturbations, one should address how each types of involved degeneracies disperse. In this work, we systematically characterize the asymptotic behavior of all types of multi-block degeneracies in NH systems using a rigorous mathematical formulation. Through a range of examples, we demonstrate that our algebraic approach can facilitate the analysis of NH degeneracies in various settings relevant to experiments.
title Characterizing all non-Hermitian degeneracies using algebraic approaches: Defectiveness and asymptotic behavior
topic Quantum Physics
Mathematical Physics
url https://arxiv.org/abs/2604.16140