##### Department of Mathematics,

University of California San Diego

****************************

### Algebra Seminar

## Skip Garibaldi

#### IPAM

## Simple groups stabilizing polynomials

##### Abstract:

The classic Linear Preserver Problem asks to determine, for a polynomial function f on a vector space V, the linear transformations g of V such that fg = f. In case f is invariant under a simple algebraic group G acting irreducibly on V , we note that the subgroup of GL(V) stabilizing f often has identity component G and we give applications realizing various groups, including the largest exceptional group E8, as automorphism groups of polynomials and algebras. We show that starting with a simple group G and an irreducible representation V, one can almost always find an f whose stabilizer has identity component G and that no such f exists in the short list of excluded cases. The main results are new even in the special case where the field is the complex numbers. This talk is about joint work with Bob Guralnick. Pre-talk for Graduate students 2:30-3:00.

Alireza Salehi Golsefidy

### October 19, 2015

### 3:00 PM

### AP&M 7218

****************************