English

Continuous and holomorphic functions with values in closed operators

Functional Analysis 2015-06-17 v3 Mathematical Physics math.MP Spectral Theory

Abstract

We systematically derive general properties of continuous and holomorphic functions with values in closed operators, allowing in particular for operators with empty resolvent set. We provide criteria for a given operator-valued function to be continuous or holomorphic. This includes sufficient conditions for the sum and product of operator-valued holomorphic functions to be holomorphic. Using graphs of operators, operator-valued functions are identified with functions with values in subspaces of a Banach space. A special role is thus played by projections onto closed subspaces of a Banach space, which depend holomorphically on a parameter.

Keywords

Cite

@article{arxiv.1309.0164,
  title  = {Continuous and holomorphic functions with values in closed operators},
  author = {Jan Dereziński and Michał Wrochna},
  journal= {arXiv preprint arXiv:1309.0164},
  year   = {2015}
}

Comments

final version, introduction reworked, 25 p

R2 v1 2026-06-22T01:18:32.597Z