## Abstract Chartrand and Stewart have shown that the line graph of an __n__βconnected graph is itself __n__βconnected. This paper shows that for every pair of integers __m__ > __n__ > 1 there is a graph of point connectivity __n__ whose line graph has point connectivity __m__. The corresponding qu
The connectivities of line and total graphs
β Scribed by Douglas Bauer; Ralph Tindell
- Publisher
- John Wiley and Sons
- Year
- 1982
- Tongue
- English
- Weight
- 371 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
Sharp lower bounds for the point connectivity and line connectivity of the line graph L(G) and the total graph T(G) of a graph G are determined. The lower bounds are expressed in terms of the point connectivity k, line connectivity Ξ», and minimum degree Ξ΄ of G. It is also shown that 2Ξ» is an upper bound for k(T(G)) and that Ξ»(T(G))= 2Ξ΄ = Ξ΄(T(G)). In each case the realizable values beyond the lower bound are determined.
π SIMILAR VOLUMES
## Abstract Let __G__ be a graph and let __V__~0~β=β{Ξ½β __V__(__G__): __d__~__G__~(Ξ½)β=β6}. We show in this paper that: (i) if __G__ is a 6βconnected line graph and if |__V__~0~|ββ€β29 or __G__[__V__~0~] contains at most 5 vertex disjoint __K__~4~'s, then __G__ is Hamiltonβconnected; (ii) every 8βco
Given a connected graph G, denote by V the family of all the spanning trees of G. Define an adjacency relation in V as follows: the spanning trees t and t$ are said to be adjacent if for some vertex u # V, t&u is connected and coincides with t$&u. The resultant graph G is called the leaf graph of G.
## Abstract The concept of the line graph can be generalized as follows. The __k__βline graph __L__~__k__~(__G__) of a graph __G__ is defined as a graph whose vertices are the complete subgraphs on __k__ vertices in __G.__ Two distinct such complete subgraphs are adjacent in __L__~__k__~(__G__) if
Thomassen conjectured that every 4-connected line graph is hamiltonian. Here we shall see that 4-connected line graphs of claw free graphs are hamiltonian connected.
Let T(G) be the tree graph of a graph G with cycle rank r. Then K ( T ( G ) ) 3 m ( G ) -r, where K(T(G)) and m(G) denote the connectivity of T ( G ) and the length of a minimum cycle basis for G, respectively. Moreover, the lower bound of m ( G ) -r is best possible.