We exhibit a rigid local system of rank six on the affine line in characteristic p=5 whose arithmetic and geometric monodromy groups are the finite group 2.J 2 (J 2 the Hall-Janko sporadic group) in one of its two (Galois-conjugate) irreducible representation of degree six.
All Science Journal Classification (ASJC) codes
- Theoretical Computer Science
- Algebra and Number Theory
- Applied Mathematics
- Exponential sums
- Representations of sporadic groups