NORTHEASTERNUNIVERSITY
MATHEMATICSDEPARTMENT


Geometry-Algebra-Singularities-Combinatorics 
Seminar

 
Totally nonnegative grassmannian and networks

 

Alexander Postnikov

(Berkeley)



 
 
 
 
 

Northeastern University

509 Lake Hall

1:30 p.m., Monday, April 16, 2001

 
 
 

Abstract: We define semiconductor networks and discuss the inverse boundary problem for them.  The "boundary
measurements" of a network produce a totally nonnegative point on a grassmannian.  The combinatorial classes of
networks give a cell decomposition of the TN part of the grassmannian.  We present a descrition of the cells and
the equivalence classes of networks.  This construction generalizes recent results of Fomin and Zelevinsky on
double Bruhat cells. 
Home Web page: Alexandru I. Suciu Created: April 12, 2001
Maintained by:  Misha Kogan URL: http://www.math.neu.edu/~GASC/gas/sottile01.html