Skip to main content
Log in

Bifurcations of Essential Spectra Generated by a Small Non-Hermitian Hole. II. Eigenvalues and Resonances

  • Research Articles
  • Published:
Russian Journal of Mathematical Physics Aims and scope Submit manuscript

Abstract

The paper focuses on bifurcations that occur in the essential spectrum of certain non-Hermitian operators. We consider an eigenvalue problem for an elliptic differential operator in a multidimensional tube-like domain which is infinite along one dimension and can be bounded or unbounded in other dimensions. This self-adjoint eigenvalue problem is perturbed by a small hole cut out of the domain. The boundary of the hole is described by a non-Hermitian Robin-type boundary condition. Our main result consists in sufficient conditions ensuring that this singular and non-Hermitian perturbation results in discrete eigenvalues or resonances bifurcating either from the edge or from certain internal points of the essential spectrum of the unperturbed problem. The location of the bifurcating eigenvalues and resonances is described in terms of asymptotic expansions with respect to the small linear size of the hole. Several illustrative examples are discussed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1.
Fig. 2.

Similar content being viewed by others

References

  1. D. I. Borisov and D. A. Zezyulin, “Bifurcations of Essential Spectra Generated by a Small Non-Hermitian Hole. I. Meromorphic Continuations”, Russ. J. Math. Phys., 28 (2021), 416–433.

    Article  MathSciNet  Google Scholar 

  2. A. M. Il’in, Matching of Asymptotic Expansions of Solutions of Boundary Value Problems, Amer. Math. Soc, Providence, RI, 1992.

    Book  Google Scholar 

  3. V. G. Maz’ya, S. A. Nazarov, and B. A. Plamenevskii, “Asymptotic Expansions of the Eigenvalues of Boundary Value Problems for the Laplace Operator in Domains With Small Holes”, Math. USSR-Izv, 24 (1985), 321–345.

    Article  Google Scholar 

  4. V. G. Maz’ya, S. A. Nazarov, and B. A. Plamenevskii, Asymptotic Theory of Elliptic Boundary Value Problems in Singularly Perturbed Domains, Birkhäuser, Basel, 2000.

    Book  Google Scholar 

  5. D. I. Borisov, D. A. Zezyulin, and M. Znojil, “Bifurcations of Thresholds in Essential Spectra of Elliptic Operators Under Localized Non-Hermitian Perturbations”, Stud. Appl. Math, 146 (2021), 834–880.

    Article  MathSciNet  Google Scholar 

Download references

Funding

The research is supported by the Russian Science Foundation (grant No. 20-11-19995).

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to D. I. Borisov or D. A. Zezyulin.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Borisov, D.I., Zezyulin, D.A. Bifurcations of Essential Spectra Generated by a Small Non-Hermitian Hole. II. Eigenvalues and Resonances. Russ. J. Math. Phys. 29, 321–341 (2022). https://doi.org/10.1134/S1061920822030037

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1134/S1061920822030037

Navigation