Title
Flows and parity subgraphs of graphs with large odd-edge-connectivity
Abstract
The odd-edge-connectivity of a graph G is the size of the smallest odd edge cut of G. Tutte conjectured that every odd-5-edge-connected graph admits a nowhere-zero 3-flow. As a weak version of this famous conjecture, Jaeger conjectured that there is an integer k such that every k-edge-connected graph admits a nowhere-zero 3-flow. Jaeger [F. Jaeger, Flows and generalized coloring theorems in graphs, J. Combin. Theory Ser. B 26 (1979) 205-216] proved that every 4-edge-connected graph admits a nowhere-zero 4-flow. Galluccio and Goddyn [A. Galluccio, L.A. Goddyn, The circular flow number of a 6-edge-connected graph is less than four, Combinatorica 22 (2002) 455-459] proved that the flow index of every 6-edge-connected graph is strictly less than 4. This result is further strengthened in this paper that the flow index of every odd-7-edge-connected graph is strictly less than 4. The second main result in this paper solves an open problem that every odd-(2k+1)-edge-connected graph contains k edge-disjoint parity subgraphs. The third main theorem of this paper proves that if the odd-edge-connectivity of a graph G is at least4@?log"2|V(G)|@?+1, then G admits a nowhere-zero 3-flow. This result is a partial result to the weak 3-flow conjecture by Jaeger and improves an earlier result by Lai et al. The fourth main result of this paper proves that every odd-(4t+1)-edge-connected graph G has a circular(2t+1)even subgraph double cover. This result generalizes an earlier result of Jaeger.
Year
DOI
Venue
2012
10.1016/j.jctb.2012.03.002
J. Comb. Theory, Ser. B
Keywords
Field
DocType
main result,odd-5-edge-connected graph,k-edge-connected graph,4-edge-connected graph,edge-connected graph,nowhere-zero 3-flow,6-edge-connected graph,large odd-edge-connectivity,graph g,parity subgraphs,odd-7-edge-connected graph,earlier result
Discrete mathematics,Combinatorics,Graph power,Graph factorization,Cubic graph,Factor-critical graph,Petersen graph,Graph minor,Universal graph,Voltage graph,Mathematics
Journal
Volume
Issue
ISSN
102
4
0095-8956
Citations 
PageRank 
References 
1
0.38
19
Authors
3
Name
Order
Citations
PageRank
Jinlong Shu19924.28
Cun-Quan Zhang249669.81
Taoye Zhang3193.73