| | |
| | |
Stat |
Members: 3643 Articles: 2'488'730 Articles rated: 2609
29 March 2024 |
|
| | | |
|
Article overview
| |
|
Topological obstructions to graph colorings | Eric Babson
; Dmitry N. Kozlov
; | Date: |
21 May 2003 | Journal: | Electron. Res. Announc. Amer. Math. Soc. 9 (2003), 61--68 | Subject: | Combinatorics; Algebraic Topology MSC-class: 05C15; 57M15, 55N91, 55T99 | math.CO math.AT | Abstract: | For any two graphs $G$ and $H$ Lovász has defined a cell complex $Hom(G,H)$ having in mind the general program that the algebraic invariants of these complexes should provide obstructions to graph colorings. Here we announce the proof of a conjecture of Lovász concerning these complexes with $G$ a cycle of odd length. More specifically, we show that: if $Hom(C_{2r+1},G)$ is $k$-connected, then $chi(G)geq k+4$. Our actual statement is somewhat sharper, as we find obstructions already in the non-vanishing of powers of certain Stiefel-Whitney classes. | Source: | arXiv, math.CO/0305300 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser claudebot
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |