TY - JOUR
T1 - On two problems in ramsey-turán theory
AU - Balogh, József
AU - Liu, Hong
AU - Sharifzadeh, Maryam
N1 - Publisher Copyright:
© 2017 Society for Industrial and Applied Mathematics.
PY - 2017
Y1 - 2017
N2 - Alon, Balogh, Keevash, and Sudakov proved that the (κ - 1)-partite Turán graph maximizes the number of distinct r-edge-colorings with no monochromatic Kκ for all fixed κ 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'fs result, the extremal construction from Ramsey.Tura7acute;n 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 Kκ free graph G with α(G) = o(n). The extremal graphs have a similar structure to the extremal graphs for the classical Ramsey.Turán problem, i.e., when the number of edges is maximized.
AB - Alon, Balogh, Keevash, and Sudakov proved that the (κ - 1)-partite Turán graph maximizes the number of distinct r-edge-colorings with no monochromatic Kκ for all fixed κ 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'fs result, the extremal construction from Ramsey.Tura7acute;n 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 Kκ free graph G with α(G) = o(n). The extremal graphs have a similar structure to the extremal graphs for the classical Ramsey.Turán problem, i.e., when the number of edges is maximized.
KW - Edge-coloring
KW - Monochromatic cliques
KW - Ramsey-Turán
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U2 - 10.1137/16M1086078
DO - 10.1137/16M1086078
M3 - Article
AN - SCOPUS:85031712530
SN - 0895-4801
VL - 31
SP - 1848
EP - 1866
JO - SIAM Journal on Discrete Mathematics
JF - SIAM Journal on Discrete Mathematics
IS - 3
ER -