We show that every graph G on n vertices with minimal degree at least n / k contains a cycle of length at least [ n / ( k -111. This verifies a conjecture of Katchalski. When k = 2 our result reduces t o the classical theorem of Dirac that asserts that if all degrees are at least i n then G is Hamil
Cycles and paths in graphs with large minimal degree
β Scribed by V. Nikiforov; R. H. Schelp
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 114 KB
- Volume
- 47
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
Let G be a simple graph of order n and minimal degree >βcn (0β<βcβ<β1/2). We prove that (1) There exist n~0~β=βn~0~(c) and kβ=βk(c) such that if nβ>βn~0~ and G contains a cycle C~t~ for some tβ>β2__k__, then G contains a cycle C~tβββ2__s__~ for some positive sβ<βk; (2) Let G be 2βconnected and nonbipartite. For each Ξ΅(0β<βΞ΅β<β1), there exists n~0~β=βn~0~(c,Ξ΅) such that if nββ₯βn~0~ then G contains a cycle C~t~ for all t with $\left \lceil { 2\over c}\right \rceil -2\leq t\leq 2(1-\varepsilon) cn$. This answers positively a question of ErdΕs, Faudree, GyΓ‘rfΓ‘s and Schelp. Β© 2004 Wiley Periodicals, Inc. J Graph Theory 47: 39β52, 2004
π SIMILAR VOLUMES
## Abstract Our main result is the following theorem. Let __k__ββ₯β2 be an integer, __G__ be a graph of sufficiently large order __n__, and __Ξ΄__(__G__)ββ₯β__n__/__k__. Then: __G__ contains a cycle of length __t__ for every even integer __t__βββ[4, __Ξ΄__(__G__)β+β1]. If __G__ is nonbipartite then
## Abstract Sufficient degree conditions for the existence of properly edgeβcolored cycles and paths in edgeβcolored graphs, multigraphs and random graphs are investigated. In particular, we prove that an edgeβcolored multigraph of order __n__ on at least three colors and with minimum colored degre
## Abstract Let __G__ be a graph of order __n__ and define __NC(G)__ = min{|__N__(__u__) βͺ __N__(__v__)| |__uv__ β __E__(__G__)}. A cycle __C__ of __G__ is called a __dominating cycle__ or __D__β__cycle__ if __V__(__G__) β __V__(__C__) is an independent set. A __D__β__path__ is defined analogously.
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.
We extend an elegant proof technique of A . G . Thomason, and deduce several parity theorems for paths and cycles in graphs. For example, a graph in which each vertex is of even degree has an even number of paths if and only if it is of even order, and a graph in which each vertex is of odd degree h