## Abstract Lower bounds on the size of a maximum bipartite subgraph of a triangleβfree __r__βregular graph are presented.
A note on maximal triangle-free graphs
β Scribed by Wayne Goddard; Daniel J. Kleitman
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 150 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
We show that a maximal triangleβfree graph on n vertices with minimum degree Ξ΄ contains an independent set of 3Ξ΄ β n vertices which have identical neighborhoods. This yields a simple proof that if the binding number of a graph is at least 3/2 then it has a triangle. This was conjectured originally by Woodall. Β© 1993 John Wiley & Sons, Inc.
π SIMILAR VOLUMES
We show that for every k β₯ 1 and Ξ΄ > 0 there exists a constant c > 0 such that, with probability tending to 1 as n β β, a graph chosen uniformly at random among all triangle-free graphs with n vertices and M β₯ cn 3/2 edges can be made bipartite by deleting Ξ΄M edges. As an immediate consequence of th
Triangle-free quasi-symmetric 2-(v, k,k) designs with intersection numbers x, y; 01, are investigated. It is proved that k β₯ 2 yx -3. As a consequence it is seen that for fixed k, there are finitely many triangle-free quasi-symmetric designs. It is also proved that: k β€ y( yx)+ x.
## Abstract It is shown that the minimum number of vertices in a triangleβfree 5βchromatic graph is at least 19.
Spin models were introduced by V. Jones (Pac. J. Math. 137 (1989), 311 334) to construct invariants of knots and links. A spin model is defined as a pair S=(X, w) of a fine set X and a function w: X\_X Γ C satisfying several axioms. Let 1=(X, E) be a connected graph with the usual metric : X\_X Γ [0