English

Boundary systems and (skew-)self-adjoint operators on infinite metric graphs

Functional Analysis 2016-06-28 v1

Abstract

We generalize the notion of Lagrangian subspaces to self-orthogonal subspaces with respect to a (skew-)symmetric form, thus characterizing (skew-)self-adjoint and unitary operators by means of self-ortho-gonal subspaces. By orthogonality preserving mappings, these characterizations can be transferred to abstract boundary value spaces of (skew-)symmetric operators. Introducing the notion of boundary systems we then present a unified treatment of different versions of boundary triples and related concepts treated in the literature. The application of the abstract results yields a description of all (skew-)self-adjoint realizations of Laplace and first derivative operators on graphs.

Keywords

Cite

@article{arxiv.1308.2635,
  title  = {Boundary systems and (skew-)self-adjoint operators on infinite metric graphs},
  author = {Carsten Schubert and Christian Seifert and Jürgen Voigt and Marcus Waurick},
  journal= {arXiv preprint arXiv:1308.2635},
  year   = {2016}
}