Combinatorics Seminar - Spring '20

When: Sunday, April 11, 10am

Where: Schreiber 309

Speaker: Tom Calvari, Tel Aviv University

Title: Graphs Without Induced Odd Cycles Are Probably Bipartite

Abstract:

In this talk, we will investigate the typical structure of a graph with a fixed number of vertices and edges and no induced copies of some fixed graph $H$.
We will discuss some of the previous work done on this problem, and present two new results:

1. For any graph $H$ with chromatic number $k > 2$, almost all graphs on $n$ vertices and with $m$ edges without induced copies of $H$ are near-$(k-1)$-partite, so long as $m$ belongs to some necessary range.

2. For $H=C_r$ an odd cycle, almost all such graphs are actually fully bipartite.

Joint work with Wojciech Samotij