Decompositions of some Specht modules I

Abstract

We give a decomposition as a direct sum of indecomposable modules of several types of Specht modules in characteristic $2$. These include the Specht modules labelled by hooks, whose decomposability was considered by Murphy. Since the main arguments are essentially no more difficult for Hecke algebras at parameter $q=-1$, we proceed in this level of generality.

21 pages. arXiv admin note: text overlap with arXiv:1704.02413, arXiv:1704.02416