## Abstract The girth pair of a graph gives the length of a shortest odd and a shortest even cycle. The existence of regular graphs with given degree and girth pair was proved by Harary and KovΓ‘cs [Regular graphs with given girth pair, J Graph Theory 7 (1983), 209β218]. A (Ξ΄, __g__)βcage is a small
The maximum valency of regular graphs with given order and odd girth
β Scribed by Guo-Hui Zhang
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 294 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
The odd girth of a graph G is the length of a shortest odd cycle in G. Let d(n, g) denote the largest k such that there exists a kβregular graph of order n and odd girth g. It is shown that d____n, g β₯ 2|n/gβ₯ if n β₯ 2__g__. As a consequence, we prove a conjecture of Pullman and Wormald, which says that there exists a 2__j__βregular graph of order n and odd girth g if and only if n β₯ gj, where g β₯ 5 is odd and j β₯ 2. A different variation of the problem is also discussed.
π SIMILAR VOLUMES
## Abstract Let __B(G)__ be the edge set of a bipartite subgraph of a graph __G__ with the maximum number of edges. Let __b~k~__ = inf{|__B(G)__|/|__E(G)__β__G__ is a cubic graph with girth at least __k__}. We will prove that lim~k β β~ __b~k~__ β₯ 6/7.
This note presents a solution to the following problem posed by Chen, Schelp, and SoltΓ©s: find a simple graph with the least number of vertices for which only the degrees of the vertices that appear an odd number of times are given.
The interval number of a graph G, denoted i(G), is the least positive integer t such that G is the intersection graph of sets, each of which is the union of t compact real intervals. It is known that every planar graph has interval number at most 3 and that this result is best possible. We investiga
## Abstract The sporadic complete 12βarc in PG(2, 13) contains eight points from a conic. In PG(2,__q__) with __q__>13 odd, all known complete __k__βarcs sharing exactly Β½(__q__+3) points with a conic π have size at most Β½(__q__+3)+2, with only two exceptions, both due to Pellegrino, which are comp