University of Cambridge > > Combinatorics Seminar > Distinct degrees and homogeneous sets

Distinct degrees and homogeneous sets

Add to your list(s) Download to your calendar using vCal

  • UserEoin Long (Birmingham)
  • ClockThursday 02 June 2022, 14:30-15:30
  • HouseMR14.

If you have a question about this talk, please contact ibl10.

In this talk I will discuss some recent work examining the extremal relationship between two well-studied graph parameters: the order of the largest homogeneous set in a graph G and the maximal number of distinct degrees appearing in an induced subgraph of G, denoted respectively by hom (G) and f(G).

Our main theorem improves estimates due to Bukh and Sudakov and to Narayanan and Tomon and shows that if G is an n-vertex graph with hom (G) at least n then f(G) > ( n / hom (G) ){1 – o(1)}. The bound here is sharp up to the o(1)-term, and asymptotically solves a conjecture of Narayanan and Tomon. In particular, this implies that max { hom (G), f(G) } > n for any n-vertex graph G, which is also sharp.

The relationship between these parameters is known to change when hom (G) < n{1/2}. I hope to discuss the suspected relationship in this other region, along with supporting results.

Joint work with Laurentiu Ploscaru.

This talk is part of the Combinatorics Seminar series.

Tell a friend about this talk:

This talk is included in these lists:

Note that ex-directory lists are not shown.


© 2006-2024, University of Cambridge. Contact Us | Help and Documentation | Privacy and Publicity