Non-self-adjoint Dirac operators on graphs

• URL: http://arxiv.org/abs/2502.00480v1
• Date: Sat, 01 Feb 2025 16:07:12 GMT
• Title: Non-self-adjoint Dirac operators on graphs
• Authors: Markus Holzmann, Václav Růžek, Matěj Tušek,
• Abstract summary: We study non-self-adjoint realizations of the Dirac operator on a finite metric graph. We derive a variant of the Birman Schwinger principle for its eigenvalues.
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• Abstract: In this paper we introduce and study generally non-self-adjoint realizations of the Dirac operator on an arbitrary finite metric graph. Employing the robust boundary triple framework, we derive, in particular, a variant of the Birman Schwinger principle for its eigenvalues, and with an example of a star shaped graph we show that the point spectrum may exhibit diverse behaviour. Subsequently, we find sufficient and necessary conditions on transmission conditions at the graph's vertices under which the Dirac operator on the graph is symmetric with respect to the parity, the time reversal, or the charge conjugation transformation.

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