The Bruhat order of the symmetric group

Richard P. Stanley
Department of Mathematics 2-375
Massachusetts Institute of Technology
Cambridge, MA 02139-4307
USA


Abstract    Full Text PDF

The Bruhat order of the symmetric group is a partial ordering of originally described by Ehresmann in order to determine the relationship among the cells of the Bruhat decomposition of the complete flag variety. We will discuss some basic properties of this partial order, including the work of Ehresmann, topological results of Verma and Björner-Wachs, the determination of the MacNeille completion by Lascoux-Schützenberger, and recent work by Postnikov and the speaker on enumerative properties of the Bruhat order related to Schubert polynomials and Schubert varieties.