We first develop some basic facts about certain sorts of rigid local systems on the affine line in characteristic p>0. We then apply them to exhibit a number of rigid local systems of rank 23 on the affine line in characteristic p=3 whose arithmetic and geometric monodromy groups are the Conway group Co3 in its orthogonal irreducible representation of degree 23.
All Science Journal Classification (ASJC) codes
- Algebra and Number Theory
- Exponential sums
- Representation theory
- Sporadic groups