English

On $\Delta$-weak $\phi$-amenability of Banach algebras

Functional Analysis 2016-03-10 v2

Abstract

Let AA be a Banach algebra and ϕΔ(A){0}\phi\in \Delta(A)\cup\{0\}. We say that AA is Δ\Delta-weak ϕ\phi-amenable if there exists an mAm\in A^{**} such that m(ϕ)=0m(\phi)=0 and m(ψ.a)=ψ(a)m(\psi.a)=\psi(a) for each ψΔ(A)\psi\in \Delta(A) and aker(ϕ)a\in \ker(\phi). It is shown that AA is Δ\Delta-weak ϕ\phi-amenable if and only if ker(ϕ)\ker(\phi) has a bounded Δ\Delta-weak approximate identity. We examine this notion for some algebras over amenable locally compact groups. Also we prove that every Δ\Delta-weak ϕ\phi-amenable Banach algebra has a bounded Δ\Delta-weak approximate identity.

Keywords

Cite

@article{arxiv.1403.2162,
  title  = {On $\Delta$-weak $\phi$-amenability of Banach algebras},
  author = {Javad Laali and Mohammad Fozouni},
  journal= {arXiv preprint arXiv:1403.2162},
  year   = {2016}
}

Comments

11 pages, some typos corrected, the converse of a theorem added and a minor revision in abstract