### Abstract

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].

Original language | English |
---|---|

Pages (from-to) | 1-11 |

Number of pages | 11 |

Journal | Electronic Research Announcements in Mathematical Sciences |

Volume | 22 |

DOIs | |

Publication status | Published - Jul 22 2015 |

### Fingerprint

### Keywords

- Extremal graph theory
- Loebl-Komlós-Sós conjecture
- Regularity lemma
- Sparse graphs
- Tree-containment problems

### ASJC Scopus subject areas

- Mathematics(all)

### Cite this

*Electronic Research Announcements in Mathematical Sciences*,

*22*, 1-11. https://doi.org/10.3934/era.2015.22.1

**The approximate Loebl-Komlós-Sós conjecture and embedding trees in sparse graphs.** / Hladký, Jan; Piguet, Diana; Simonovits, M.; Stein, Maya; Szemerédi, E.

Research output: Contribution to journal › Article

*Electronic Research Announcements in Mathematical Sciences*, vol. 22, pp. 1-11. https://doi.org/10.3934/era.2015.22.1

}

TY - JOUR

T1 - The approximate Loebl-Komlós-Sós conjecture and embedding trees in sparse graphs

AU - Hladký, Jan

AU - Piguet, Diana

AU - Simonovits, M.

AU - Stein, Maya

AU - Szemerédi, E.

PY - 2015/7/22

Y1 - 2015/7/22

N2 - 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].

AB - 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].

KW - Extremal graph theory

KW - Loebl-Komlós-Sós conjecture

KW - Regularity lemma

KW - Sparse graphs

KW - Tree-containment problems

UR - http://www.scopus.com/inward/record.url?scp=84937435535&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84937435535&partnerID=8YFLogxK

U2 - 10.3934/era.2015.22.1

DO - 10.3934/era.2015.22.1

M3 - Article

VL - 22

SP - 1

EP - 11

JO - Electronic Research Announcements in Mathematical Sciences

JF - Electronic Research Announcements in Mathematical Sciences

SN - 1935-9179

ER -