Title
Nowhere-Zero 5-Flows and Even (1,2)-Factors
Abstract
graph G = ( V , E ) admits a nowhere-zero k -flow if there exists an orientation H = ( V , A ) of G and an integer flow $${\varphi:A \to \mathbb{Z}}$$ such that for all $${a \in A, 0 < |\varphi(a)| < k}$$ . Tutte conjectured that every bridgeless graphs admits a nowhere-zero 5-flow. A (1,2)-factor of G is a set $${F \subseteq E}$$ such that the degree of any vertex v in the subgraph induced by F is 1 or 2. Let us call an edge of G , F - balanced if either it belongs to F or both its ends have the same degree in F . Call a cycle of G F - even if it has an even number of F -balanced edges. A (1,2)-factor F of G is even if each cycle of G is F -even. The main result of the paper is that a cubic graph G admits a nowhere-zero 5-flow if and only if G has an even (1,2)-factor.
Year
DOI
Venue
2008
10.1007/s00373-011-1119-x
Graphs and Combinatorics
Keywords
Field
DocType
nowhere-zero flow factor,spanning tree,cubic graph
Discrete mathematics,Combinatorics,Line graph,Gray graph,Cubic graph,Cycle graph,Distance-hereditary graph,Symmetric graph,Universal graph,Mathematics,Complement graph
Journal
Volume
Issue
ISSN
29
3
Electronic Notes in Discrete Mathematics
Citations 
PageRank 
References 
0
0.34
4
Authors
2
Name
Order
Citations
PageRank
Martín Matamala115821.63
José Zamora275.95