Simplicial (Co)-homology of

Autor: Frédéric Gourdeau, Yasser Farhat
Rok vydání: 2018
Předmět:
Zdroj: Canadian Mathematical Bulletin. 62:756-766
ISSN: 1496-4287
0008-4395
DOI: 10.4153/s0008439518000644
Popis: We consider the unital Banach algebra$\ell ^{1}(\mathbb{Z}_{+})$and prove directly, without using cyclic cohomology, that the simplicial cohomology groups${\mathcal{H}}^{n}(\ell ^{1}(\mathbb{Z}_{+}),\ell ^{1}(\mathbb{Z}_{+})^{\ast })$vanish for all$n\geqslant 2$. This proceeds via the introduction of an explicit bounded linear operator which produces a contracting homotopy for$n\geqslant 2$. This construction is generalised to unital Banach algebras$\ell ^{1}({\mathcal{S}})$, where${\mathcal{S}}={\mathcal{G}}\cap \mathbb{R}_{+}$and${\mathcal{G}}$is a subgroup of $\mathbb{R}_{+}$.
Databáze: OpenAIRE