The approximate Loebl-Komlós--Sós conjecture and embedding trees in sparse graphs

0443855 - MÚ 2016 RIV US eng J - Journal Article
Hladký, Jan - Piguet, Diana - Simonovits, M. - Stein, M. - Szemerédi, E.
The approximate Loebl-Komlós--Sós conjecture and embedding trees in sparse graphs.
Electronic Research Announcements in Mathematical Sciences. Roč. 22, April (2015), s. 1-11. ISSN 1935-9179. E-ISSN 1935-9179
R&D Projects: GA MŠMT(CZ) 1M0545
Institutional support: RVO:67985840 ; RVO:67985807
Keywords : extremal graph theory * Loebl-Komlós-Sós conjecture * regularity lemma
Subject RIV: BA - General Mathematics
Impact factor: 0.333, year: 2015
http://www.aimsciences.org/journals/displayArticlesnew.jsp?paperID=11110

Loebl, Komlós and Sós conjectured that every n-vertex graph G with at least n/2 vertices of degree at least k contains each tree T of order k+1 as a subgraph. We give a sketch of a proof of the approximate version of this conjecture for large values of k. For our proof, we use a structural decomposition which can be seen as an analogue of Szemerédi's regularity lemma for possibly very sparse graphs. With this tool, each graph can be decomposed into four parts: a set of vertices of huge degree, regular pairs (in the sense of the regularity lemma), and two other objects each exhibiting certain expansion properties. We then exploit the properties of each of the parts of G to embed a given tree T. The purpose of this note is to highlight the key steps of our proof. Details can be found in [arXiv:1211.3050].
Permanent Link: http://hdl.handle.net/11104/0246512