On integral Ext² between certain Weyl modules of GLn

2024/11/01 by Metzaki, Maria
#20G05 #FOS: Mathematics #Representation Theory (math.RT)

paper · doi:10.48550/arxiv.2411.00675

Abstract

Consider partitions of the form λ=(a,1^b) and μ=(a+1,b-1), where a+1>b-1. In this paper, we determine the extension groups Ext_A²(K_λF,K_μF), where F is a free ℤ-module of finite rank n, K_λF and K_μF are the Weyl modules of the general linear group GL_n(ℤ) corresponding to λ and μ, respectively, A=S_ℤ(n,r) is the integral Schur algebra and r=a+b.

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