In this paper we shall show that if G = (V,E) is a bipartite graph with more than (a -1)j YJ + (b -1)1X1 -(a -l)(b -1) edges, where (X, Y) is a vertex-partition for G and a < b are natural numbers with a < 1x1, b < 1 YI, then G contains every tree T with bipartitenumbers a < b. This result is relate
Constructing trees in graphs with no K2,s
β Scribed by Suman Balasubramanian; Edward Dobson
- Book ID
- 102345562
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 150 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
Let sββ₯β2 be an integer and kβ>β12(sβββ1) an integer. We give a necessary and sufficient condition for a graph G containing no K~2,s~ with $\delta(G)\ge{k}/2$ and $\Delta(G)\ge k$ to contain every tree T of order kβ+β1. We then show that every graph G with no K~2,s~ and average degree greater than kβββ1 satisfies this condition, improving a result of Haxell, and verifying a special case of the ErdΕsβSΓ³s conjecture, which states that every graph of average degree greater than kβββ1 contains every tree of order kβ+β1. Β© 2007 Wiley Periodicals, Inc. J Graph Theory 56: 301β310, 2007
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