Toughness, minimum degree, and the existence of 2-factors
β Scribed by D. Bauer; E. Schmeichel
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 690 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
Degree conditions on the vertices of a tβtough graph G(1 β¦ t β¦ 2) that ensure the existence of a 2βfactor in G are presented. These conditions are asymptotically best possible for every t Ο΅ [1, 3/2] and for infinitely many t Ο΅ [3/2, 2].
π SIMILAR VOLUMES
## Theorem 2. Let G be a 2-tough graph. Then for any function f : V(G)+ { 1, 2) such that C xsvCcj f (x) in euen, G has an f-factor. Before stating the second main theorem of this paper it is necessary to make the following definition. Let G be a graph and let g and f be two integer-valued functi
In a paper with the same title (Enomoto et al., 1985) we proved Chv&al's conjecture that ktough graphs have k-factors if they satisfy trivial necessary conditions. In this paper, we introduce a variation of toughness, and prove a stronger result for the existence of l-or 2-factors. This solves a con
## Abstract Let __k__ be an integer such that β¦, and let __G__ be a connected graph of order __n__ with β¦, __kn__ even, and minimum degree at least __k__. We prove that if __G__ satisfies max(deg(u), deg(v)) β¦ n/2 for each pair of nonadjacent vertices __u, v__ in __G__, then __G__ has a __k__βfacto
A graph is called K1,.-free if it contains no K l , n as an induced subgraph. Let n ( r 3), r be integers (if r is odd, r 2 n -1). We prove that every Kl,,-free connected graph G with rlV(G)I even has an r-factor if its minimum degree is at least This degree condition is sharp.
## Abstract We write __H__βββ__G__ if every 2βcoloring of the edges of graph __H__ contains a monochromatic copy of graph __G__. A graph __H__ is __G__β__minimal__ if __H__βββ__G__, but for every proper subgraph __H__β² of __H__, __H__β²βββ__G__. We define __s__(__G__) to be the minimum __s__ such th