A tower lower bound for the degree relaxation of the Regularity Lemma
Combinatorics
2024-10-16 v2
Abstract
It is well-known that if is an -regular pair (in the sense of Szemer\'edi) then there exist sets and with and so that the degrees of all vertices in differ by at most and the degrees of all vertices in differ by at most . We call such a property "-degularity". This leads to the notion of an "-degular" partition of a graph in the same way as the definition of -regular pairs leads to the notion of -regular partitions. We show that there exist graphs in which any -degular partition requires the number of clusters to be . That is, even though degularity is a substantial relaxation of regularity, in general one cannot improve much on the bounds that come with Szemer\'edi's regularity lemma.
Cite
@article{arxiv.2410.05023,
title = {A tower lower bound for the degree relaxation of the Regularity Lemma},
author = {Frederik Garbe and Jan Hladký},
journal= {arXiv preprint arXiv:2410.05023},
year = {2024}
}
Comments
13 pages, 1 figure