NORTHEASTERN UNIVERSITY
MATHEMATICS DEPARTMENT
 
Geometry-Algebra-Singularities-Combinatorics 
Seminar
 
 
A stable range for dimensions of homogeneous O(n)-invariant polynomials on the n by n matrices. 
 
 

Jeb Willenbring

(Yale University )
 
 

Northeastern University

509 Lake Hall

1:30 p.m., Monday, March 5, 2001

 
 
Abstract:   We will consider the case where the complex orthogonal group, O(n,C) acts on the n by n matrices by restricting the adjoint representation of GL(n,C). This provides an action on the ring of complex valued polynomial functions on the matrices. A combinatorial description of an initial segment of the Hilbert series for the invariant polynomials under this action will be described. The combinatorics relates certain sums over Littlewood-Richardson coefficients to the enumeration of cyclic graphs with directed edges. This relationship is established via representation theory of the symmetric group.
 
Home Web page:  Alexandru I. Suciu  Created: Feb. 10, 2000   
Maintained by:  Carol Chang  URL: http://www.math.neu.edu/~GASC/gas/willenbring.html