English

On Character Amenability of Banach Algebras

Functional Analysis 2008-07-24 v2

Abstract

Associated to a nonzero homomorphism φ\varphi of a Banach algebra AA, we regard special functionals, say mφm_\varphi, on certain subspaces of AA^\ast which provide equivalent statements to the existence of a bounded right approximate identity in the corresponding maximal ideal in AA. For instance, applying a fixed point theorem yields an equivalent statement to the existence of a mφm_\varphi on AA^\ast; and, in addition we expatiate the case that if a functional mφm_\varphi is unique, then mφm_\varphi belongs to the topological center of the bidual algebra AA^{\ast\ast}. An example of a function algebra, surprisingly, contradicts a conjecture that a Banach algebra AA is amenable if AA is φ\varphi-amenable in every character φ\varphi and if functionals mφm_\varphi associated to the characters φ\varphi are uniformly bounded. Aforementioned are also elaborated on the direct sum of two given Banach algebras.

Keywords

Cite

@article{arxiv.0712.2072,
  title  = {On Character Amenability of Banach Algebras},
  author = {Ahmadreza Azimifard},
  journal= {arXiv preprint arXiv:0712.2072},
  year   = {2008}
}

Comments

Keywords: Banach algebra, topological center, amenability