PSU(3,5) Modulo 5

The Hecke algebra for the Projective Special Unitary Group of dimension 3 over GF(5) with point stabilizer being the normalizer of a Sylow 5-subgroup in characteristic 5 .

The Module M

The module M is the permutation module over the field of chacteristic 5, having point stablilizer of order 1000 . The dimension of M is 126 .

The dimensions of the irreducible submodules modules are 125, 1 .

The module M is semi-simple. It has composition factors 1, 2

The Action Algebra

The action algebra A is the image of kG in the k-endomorphism ring of M. It's simple modules are the irreducible submodules of M.

The algebra A is a direct product of matrix algebras of dimension 125, 1 over field extensions of the base field of degrees 1, 1 .