Decomposition of idempotent 2-cocycles

2022/03/01 by Christos Lamprakis, Lamprakis, Christos, T. Theohari-Apostolidi +1
Mathematics · #Algebraic structures and combinatorial models #FOS: Mathematics #Homotopy and Cohomology in Algebraic Topology #Primary 16S35 #Rings and Algebras (math.RA) #Rings, Modules, and Algebras #Secondary 11S35

paper · pdf · doi:10.48550/arxiv.2203.00589

openalex publication_date 2022/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Let L be a finite Galois extension of K with Galois group G. We decompose any idempotent 2-cocycle f using finite sequences of descending two-sided ideals of the corresponding weak crossed product algebra A:= (L/k, G, f). We specialise the results in case f is the corresponding idempotent 2-cocycle for some semilinear map from G to a multiplicative monoid with minimum element.

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