====== Zhexiu Tu (Cornell) ======

====== Topological Representations of Matroids and the cd-Index ======

===== Abstract for the Combinatorics Seminar 2017 February 28 =====

There are several different topological representations of non-orientable matroids. In this talk, inspired by Swartz's work, I will show an explicit homotopy sphere arrangement that is a regular CW-complex whose intersection lattice is the geometric lattice of the corresponding matroid. I will also look at enumerative properties, including how the flag f-vector formula of Billera, Ehrenborg, and Readdy for oriented matroids applies to arbitrary matroids.


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