Department of Mathematics

Seminar in Cluster algebras

  •  John Machacek, York University
  •  Sign variation and boundary measurement in projective space
  •  04/04/2019
  •  3:00 PM - 4:00 PM
  •  C204A Wells Hall

We are interested in the topology of some spaces obtained by relaxing total positivity in the real Grassmannian. We define two families of subsets of the Grassmannian each of which include both the totally nonnegative Grassmannian and the whole Grassmannian. In this initial study of such subsets of the Grassmannian we focus of subsets of real projective space where interesting topology already appears. We we are able to find a regular CW complex which can be leveraged to compute some invariants like the fundamental group and Euler characteristic. We also conjecture some "ball-like" properties (e.g. Cohen-Macualayness).



Department of Mathematics
Michigan State University
619 Red Cedar Road
C212 Wells Hall
East Lansing, MI 48824

Phone: (517) 353-0844
Fax: (517) 432-1562

College of Natural Science