Branching rules for Specht modules

Let S-lambda be a Specht module for the symmetric group Sigma(n) defined over a field of characteristic different from 2, and let L-n-1 be the sum of all transpositions in Sigma(n)-1 that do not fix n - 1. It is shown that the minimal polynomial of L-n-1 acting on S lambda has maximum possible degree. As a consequence, the indecomposable components of the restriction of S-lambda to Sigma(n)-1 coincide with the block components. Analogous results are proved for L-n+1 and the Sigma(n)+1 -module that is induced from S-lambda. (C) 2006 Elsevier Inc. All rights reserved.