Paper Abstract


Higher extensions between modules for SL_2


We calculate Ext^*_{SL_2(k)}(\Delta(\lambda), \Delta(\mu)), Ext^*_{SL_2(k)}(L(\lambda), \Delta(\mu)), Ext^*_{SL_2(k)}(\Delta(\lambda), L(\mu)), and Ext^*_{SL_2(k)}(L(\lambda), L(\mu)), where \Delta(\lambda) is the Weyl module of highest weight \lambda, L(\lambda) is the simple SL_2(k)-module of highest weight \lambda and our field k is algebraically closed of positive characteristic. We also get analogous results for the Dipper-Donkin quantisation.

This page last modified by Alison Parker on Mon Aug 30 2004