Title
Largest 2-Regular Subgraphs in 3-Regular Graphs
Abstract
For a graph G, let $$f_2(G)$$ denote the largest number of vertices in a 2-regular subgraph of G. We determine the minimum of $$f_2(G)$$ over 3-regular n-vertex simple graphs G. To do this, we prove that every 3-regular multigraph with exactly c cut-edges has a 2-regular subgraph that omits at most $$\max \{0,\lfloor (c-1)/2\rfloor \}$$ vertices. More generally, every n-vertex multigraph with maximum degree 3 and m edges has a 2-regular subgraph that omits at most $$\max \{0,\lfloor (3n-2m+c-1)/2\rfloor \}$$ vertices. These bounds are sharp; we describe the extremal multigraphs.
Year
DOI
Venue
2019
10.1007/s00373-019-02021-6
Graphs and Combinatorics
Keywords
Field
DocType
Factors in graphs, Cubic graphs, Cut-edges, 05C07, 05C70, 05C35
Graph,Combinatorics,Multigraph,Vertex (geometry),Cubic graph,Degree (graph theory),Mathematics
Journal
Volume
Issue
ISSN
35
4
0911-0119
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Ilkyoo Choi12612.04
ringi kim272.96
Alexandr V. Kostochka368289.87
boram park455.89
Douglas B. West51176185.69