Existence of spanning and dominating trails and circuits
β Scribed by H. J. Veldman
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 445 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Let T be a trail of a graph G. T is a spanning trail (S-trail) if T contains all vertices of G. Tis a dominating trail (D-trail) if every edge of G is incident with a t least one vertex of T. A circuit is a nontrivial closed trail.
Sufficient conditions involving lower bounds on the degree-sum of vertices or edges are derived for graphs to have an S-trail, S-circuit, D-trail, or D-circuit. Thereby a result of Brualdi and Shanny and one mentioned by Lesniak-Foster and Williamson are improved.
π SIMILAR VOLUMES
## Abstract Suppose __G__ is a simple connected __n__βvertex graph. Let Ο~3~(__G__) denote the minimum degree sum of three independent vertices in __G__ (which is β if __G__ has no set of three independent vertices). A 2β__trail__ is a trail that uses every vertex at most twice. Spanning 2βtrails g
## Abstract We deal with conditions for a digraph of minimum degree __r__ which imply the existence of a vertex __x__ contained in __r__ circuits which have pairwise only __x__ in common. In particular, we give some positive answers to a question of P. Seymour, whether an __r__βregular digraph has
## Abstract Let __G__ be a graph and __f__ be a mapping from __V__(__G__) to the positive integers. A subgraph __T__ of __G__ is called an __f__βtree if __T__ forms a tree and __d__~__T__~(__x__)β€__f__(__x__) for any __x__β__V__(__T__). We propose a conjecture on the existence of a spanning __f__βt