2025 : 9 : 7
Esmaeil Feizi

Esmaeil Feizi

Academic rank: Assistant Professor
ORCID:
Education: PhD.
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Faculty: Faculty of Science
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Research

Title
The first Hochschild cohomology groups of ultrapowers of Banach algebra with coefficients in some special Banach bimodules
Type
JournalPaper
Keywords
Ultrapower · First Hochschild cohomology groups · Point derivations · Ultra φ-amenability · Point derivations · Ultra-character amenability · Ultra-character contractibility · Lau product
Year
2024
Journal INDIAN JOURNAL OF PURE & APPLIED MATHEMATICS
DOI
Researchers Vania Khodakarami ، Esmaeil Feizi

Abstract

We consider a Banach algebra A, a nonzero element ϕ in ∆(A)∪ {0}, and a Banach A-bimodule X. We investigate ultrapowers denoted as (A)U and (ϕ), along with treating (X)U as a Banach (A)U -bimodule. We analyze H1((A)U ,(X)U ), with the constraint that (X)U ∈ SM(A)U(ϕ). Moreover, we establish a connection between H1((A)U , C) vanishing and H1((A)U ,(X)U ) vanishing. Subsequently, we relax the symmetry conditions of SM(A)U(ϕ)and explore character contractibility and character amenability of (A)U , which is referred to as ultracharacter contractibility and ultra-character amenability of A. In particular, we verify the ultra-character amenability for Lau products and group algebras.