English

A degree sequence Hajnal--Szemer\'edi theorem

Combinatorics 2016-01-25 v2

Abstract

We say that a graph GG has a perfect HH-packing if there exists a set of vertex-disjoint copies of HH which cover all the vertices in GG. The seminal Hajnal--Szemer\'edi theorem characterises the minimum degree that ensures a graph GG contains a perfect KrK_r-packing. Balogh, Kostochka and Treglown proposed a degree sequence version of the Hajnal--Szemer\'edi theorem which, if true, gives a strengthening of the Hajnal--Szemer\'edi theorem. In this paper we prove this conjecture asymptotically. Another fundamental result in the area is the Alon--Yuster theorem which gives a minimum degree condition that ensures a graph contains a perfect HH-packing for an \emph{arbitrary} graph HH. We give a wide-reaching generalisation of this result by answering another conjecture of Balogh, Kostochka and Treglown on the degree sequence of a graph that forces a perfect HH-packing. We also prove a degree sequence result concerning perfect transitive tournament packings in directed graphs. The proofs blend together the regularity and absorbing methods.

Keywords

Cite

@article{arxiv.1412.1774,
  title  = {A degree sequence Hajnal--Szemer\'edi theorem},
  author = {Andrew Treglown},
  journal= {arXiv preprint arXiv:1412.1774},
  year   = {2016}
}

Comments

22 pages, 2 figures, to appear in JCTB

R2 v1 2026-06-22T07:20:52.583Z