**Date & Time:** Wednesday, July 13, 2016, 11:00-12:00

**Venue:** Ramanujan Hall

**Title:**Binomial regularity of trees.

**Speaker: **Prof. N. Narayanan, Dept of Maths, IIT-Madras

**Abstract:** Edge ideals of graphs and the relation between their algebraic properties and the graph invariants is receiving a lot of attention in the recent years.
In this talk we present improved lower bound for the regularity of the binomial edge ideals of trees. We then prove an upper bound for the regularity of the binomial edge ideals proposed by Saeedi Madani and Kiani for a subclass of block graphs, which in particular contain lobsters. We further show that except for trees containing what we call a jewel as a subgraph, the regularity is one more than the number of internal vertices.
This talk is based on a joint work with my colleagues A V Jayanthan and B V Raghavendra Rao.