Title
Extremal graphs with local covering conditions
Abstract
We systematically study a natural problem in extremal graph theory, to minimize the number of edges in a graph with a fixed number of vertices, subject to a certain local condition: each vertex must be in a copy of a fixed graph H. We completely solve this problem when H is a clique, as well as more generally when H is any regular graph with degree at least about half its number of vertices. We also characterize the extremal graphs when H is an Erdos-Renyi random graph. The extremal structures turn out to have the similar form as the conjectured extremal structures for a well-studied but elusive problem of similar flavor with local constraints: to maximize the number of copies of a fixed clique in graphs in which all degrees have a fixed upper bound.
Year
DOI
Venue
2020
10.1137/19M1286712
SIAM JOURNAL ON DISCRETE MATHEMATICS
Keywords
DocType
Volume
extremal graph theory,local covering,random graphs
Journal
34
Issue
ISSN
Citations 
2
0895-4801
0
PageRank 
References 
Authors
0.34
0
2
Name
Order
Citations
PageRank
Chakraborti Debsoumya100.34
Po-Shen Loh213318.68