English

Compactness of derivations from commutative Banach algebras

Functional Analysis 2009-11-02 v1

Abstract

We consider the compactness of derivations from commutative Banach algebras into their dual modules. We show that if there are no compact derivations from a commutative Banach algebra, AA, into its dual module, then there are no compact derivations from AA into any symmetric AA-bimodule; we also prove analogous results for weakly compact derivations and for bounded derivations of finite rank. We then characterise the compact derivations from the convolution algebra 1(Z+)\ell^1(\Z_+) to its dual. Finally, we give an example (due to J. F. Feinstein) of a non-compact, bounded derivation from a uniform algebra AA into a symmetric AA-bimodule.

Keywords

Cite

@article{arxiv.0910.5902,
  title  = {Compactness of derivations from commutative Banach algebras},
  author = {Matthew J. Heath},
  journal= {arXiv preprint arXiv:0910.5902},
  year   = {2009}
}