Brandeis University Everyperson Seminar

Monday December 13, 2004, 4 PM, Goldsmith 317

tea at 3:30 PM at the Math Department lounge (Goldsmith 300)

Speaker: Sasha Golubeva (Hebrew University)

Title: Linear groups-subgroups pairs with the same invariants

Abstract: We consider the problem of finding all complex linear algebraic group-subgroup pairs such that the rational invariants of the group and the subgroup coincide. We call them exceptional pairs.

As follows from the main theorem of Galois theory, a finite group is uniquely determined by its invariants. In other words, if G is finite and H is proper subgroup, then the pair (H,G) is not exceptional. A classification of exceptional pairs for a certain type of groups shows to what extent a group of this type is determined by its invariants.