Relative length of long paths and cycles in graphs with large degree sums
โ Scribed by Hikoe Enomoto; Jan van den Heuvel; Atsushi Kaneko; Akira Saito
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 601 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
For a graph G, p(G) denotes the order of a longest path in G and c(G) the order of a longest cycle. We show that if G is a connected graph n โฅ 3 vertices such that d(u) + d(v) + d(w) โง n for all triples u, v, w of independent vertices, then G satisfies c(G) โฅ p(G) โ 1, or G is in one of six families of exceptional graphs. This generalizes results of Bondy and of Bauer, Morgana, Schmeichel, and Veldman. ยฉ 1995, John Wiley & Sons, Inc.
๐ SIMILAR VOLUMES
We present and prove several results concerning the length of longest cycles in 2connected or I-tough graphs with large degree sums. These results improve many known results on long cycles in these graphs. We also consider the sharpness of the results and discuss some possible strengthenings.
## Abstract Let __G__ be a simple graph of order __n__ and minimal degree >โcn (0โ<โcโ<โ1/2). We prove that (1) There exist __n__~0~โ=โ__n__~0~(__c__) and __k__โ=โ__k__(__c__) such that if __n__โ>โ__n__~0~ and __G__ contains a cycle __C__~__t__~ for some __t__โ>โ2__k__, then __G__ contains a cycle
## Abstract Our main result is the following theorem. Let __k__โโฅโ2 be an integer, __G__ be a graph of sufficiently large order __n__, and __ฮด__(__G__)โโฅโ__n__/__k__. Then: __G__ contains a cycle of length __t__ for every even integer __t__โโโ[4, __ฮด__(__G__)โ+โ1]. If __G__ is nonbipartite then
Let G be a graph of order n satisfying d(u) + d(v) โฅ n for every edge uv of G. We show that the circumference-the length of a longest cycle-of G can be expressed in terms of a certain graph parameter, and can be computed in polynomial time. Moreover, we show that G contains cycles of every length be