From: Kelli McGee \(Kelly Services Inc\) (a-kellim@microsoft.com)
Date: Wed Mar 10 2004 - 09:40:15 PST
You are invited to attend...
************************************************************************
*****************************
WHO: Julianna Tymoczko
AFFILIATION: University of Michigan
TITLE: Generating Unipotent Groups Efficiently
WHEN: Mon 3/15/2004
WHERE: 113/1021 Research Lecture Room, Microsoft Research
TIME: 3:30PM-5:00PM
HOST: Henry Cohn
************************************************************************
******************************
ABSTRACT:
I discuss unipotent groups over Z/pZ, namely the subgroup of
upper-triangular matrices with ones along the diagonal and entries in
Z/pZ. When trying to determine how to generate a given matrix
efficiently, it is natural to start with unipotent matrices because of a
classical theorem that expresses every invertible matrix as a product of
two unipotent matrices and one permutation.
In this talk I give a construction showing the best known diameter of
the unipotent group over Z/pZ, which is O(n^2 log p). I also sketch a
proof that this is the best possible bound.
Time permitting, I also discuss how the same construction can be used to
describe unipotent groups in other matrix groups, as well as to
understand the structure and the permutation groups associated to those
matrix groups.
This is joint work with Jordan Ellenberg.
BIO:
Julianna Tymoczko works in algebraic combinatorics, Lie theory, and
algebraic geometry. Much of her research studies the geometry of flag
varieties and their subvarieties. She received her Ph.D. from Princeton
University under the supervision of Bob MacPherson and is currently at
the University of Michigan.
_______________________________________________
Theory-group mailing list
Theory-group@cs.washington.edu
http://mailman.cs.washington.edu/mailman/listinfo/theory-group
This archive was generated by hypermail 2.1.6 : Wed Mar 10 2004 - 09:40:33 PST