Abstract
The following conjecture may have never been explicitly stated, but seems to have been floating around: if the vertex set of a graph with maximal degree Δ is partitioned into sets V i of size 2Δ, then there exists a coloring of the graph by 2Δ colors, where each color class meets each V i at precisely one vertex. We shall name it the strong 2Δ-colorability conjecture. We prove a fractional version of this conjecture. For this purpose, we prove a weighted generalization of a theorem of Haxell, on independent systems of representatives (ISR's). En route, we give a survey of some recent developments in the theory of ISR's.
Original language | English |
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Pages (from-to) | 253-267 |
Number of pages | 15 |
Journal | Combinatorica |
Volume | 27 |
Issue number | 3 |
DOIs | |
State | Published - May 2007 |
Externally published | Yes |
Bibliographical note
Funding Information:* The research of the first author was supported by grant no 780/04 from the Israel Science Foundation, and grants from the M. & M. L. Bank Mathematics Research Fund and the fund for the promotion of research at the Technion. † The research of the third author was supported by the Sacta–Rashi Foundation.
ASJC Scopus subject areas
- Discrete Mathematics and Combinatorics
- Computational Mathematics