Sept 18 
Richard Ehrenborg
University of Kentucky 
Simion's type B associahedron is a pulling triangulation
of the Legendre polytope
We show that the Simion type B associahedron is combinatorially equivalent to a pulling triangulation of the type A root polytope known as the Legendre polytope. Furthermore, we show that every pulling triangulation of the boundary of the Legendre polytope yields a flag complex. Our triangulation refines a decomposition of the boundary of the Legendre polytope given by Cho. This is joint work with Gábor Hetyei and Margaret Readdy. 
Sept 25 
Zhexiu Tu
Centre College 
Topological Representations of Matroids and the cdindex
There are several different topological representations of nonorientable matroids. In this talk, inspired by Swartz's work, I will show an explicit fully partitioned homotopy sphere darrangement S that is a CWcomplex whose intersection lattice is the geometric lattice of the corresponding matroid for matroids of rank < 5. Moreover S has a dsphere in it that is a regular CWcomplex. We will also look at enumerative properties, including how the flag fvector formula of Billera, Ehrenborg and Readdy for oriented matroids applies to arbitrary matroids. 
Oct 2 
Alex Happ
University of Kentucky 
TBA

Oct 9 
Olsen McCabe
University of Kentucky 
TBA

Oct 16 
Brian Davis
University of Kentucky 
Regular triangulations and Gröbner bases

Oct 23 
No meeting


Oct 30 
Rafael González D'león
Universidad Sergio Arboleda and York University 
The Whitney dual of a graded poset

Nov 6 
Megan Bernstein
Georgia Tech 
TBA

Nov 13 
Radmila Sazdanovic
NC State University 
TBA

Nov 20 
Open date


Nov 27 
Joseph Cummings
University of Kentucky 
TBA

Dec 4 
Open date


Last updated September 15, 2017.