Twisted Schubert polynomials

Series
Combinatorics Seminar
Time
Friday, October 18, 2019 - 3:00pm for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Ricky Liu – North Carolina State University – riliu@ncsu.eduhttps://riliu.math.ncsu.edu/
Organizer
Josephine Yu

We will describe a twisted action of the symmetric group on the polynomial ring in n variables and use it to define a twisted version of Schubert polynomials. These twisted Schubert polynomials are known to be related to the Chern-Schwartz-MacPherson classes of Schubert cells in the flag variety. Using properties of skew divided difference operators, we will show that these twisted Schubert polynomials are monomial positive and give a combinatorial formula for their coefficients.