Chennai Mathematical Institute


Research seminar by MSc students
11:50 - 1:05, Seminar Hall
Cohen- Macauley posets and the homotopy complementation formula

Naageswaran M
Chennai Mathematical Institute.


Understanding the topological behavior of partially ordered sets (i.e., posets ) is often detrimental to resolve problems arising in the algebraic and combinatorial context. Cohen-Macauley Poset is a class of posets that occurs frequently in such problems. Determining whether a poset is Cohen-Macauley is a tricky task. However, for certain classes of posets such as semi-modular and supersolvable lattices, the homotopy complementation formula due to Bjorner and Walker serves as a useful tool. In this talk, I will present the proof of this formula and use it determine the homotopy type of the partition lattice.