Title
On Two Problems in Ramsey-Turán Theory.
Abstract
Alon, Balogh, Keevash, and Sudakov proved that the (k-1)-partite Turan graph maximizes the number of distinct r-edge-colorings with no monochromatic K-k for all fixed k and r = 2, 3, among all n-vertex graphs. In this paper, we determine this function asymptotically for r = 2 among n-vertex graphs with a sublinear independence number. Somewhat surprisingly, unlike Alon, Balog, Keevash, and Sudakov's result, the extremal construction from Ramsey-Turan theory, as a natural candidate, does not maximize the number of distinct edge-colorings with no monochromatic cliques among all graphs with a sublinear independence number, even in the 2-colored case. In the second problem, we determine the maximum number of triangles asymptotically in an n-vertex K-k free graph G with alpha(G) = o(n). The extremal graphs have a similar structure to the extremal graphs for the classical Ramsey-Turan problem, i.e., when the number of edges is maximized.
Year
DOI
Venue
2017
10.1137/16M1086078
SIAM JOURNAL ON DISCRETE MATHEMATICS
Keywords
Field
DocType
Ramsey-Turan,edge-coloring,monochromatic cliques
Discrete mathematics,Graph,Independence number,Combinatorics,Monochromatic color,Chordal graph,Mathematics
Journal
Volume
Issue
ISSN
31
3
0895-4801
Citations 
PageRank 
References 
0
0.34
4
Authors
3
Name
Order
Citations
PageRank
József Balogh186289.91
Hong Liu2398.54
Maryam Sharifzadeh3113.83