2022
On a colored Turan problem of Diwan and Mubayi
LAMAISON VIDARTE, Ander, Alp MUYESSER a Michael TAITZákladní údaje
Originální název
On a colored Turan problem of Diwan and Mubayi
Autoři
LAMAISON VIDARTE, Ander (724 Španělsko, domácí), Alp MUYESSER a Michael TAIT
Vydání
Discrete Mathematics, Elsevier B. V. 2022, 0012-365X
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10201 Computer sciences, information science, bioinformatics
Stát vydavatele
Nizozemské království
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 0.800
Kód RIV
RIV/00216224:14330/22:00128972
Organizační jednotka
Fakulta informatiky
UT WoS
000831721100007
Klíčová slova anglicky
Turán number; Erdős-Stone theorem; Regularity
Změněno: 6. 4. 2023 11:32, RNDr. Pavel Šmerk, Ph.D.
Anotace
V originále
Suppose that R (red) and B (blue) are two graphs on the same vertex set of size n, and H is some graph with a red-blue coloring of its edges. How large can R and B be if R∪B does not contain a copy of H? Call the largest such integer mex(n,H). This problem was introduced by Diwan and Mubayi, who conjectured that (except for a few specific exceptions) when H is a complete graph on k+1 vertices with any coloring of its edges mex(n,H)=ex(n,Kk+1). This conjecture generalizes Turán's theorem. Diwan and Mubayi also asked for an analogue of Erdős-Stone-Simonovits theorem in this context. We prove the following upper bound on the extremal threshold in terms of the chromatic number χ(H) and the reduced maximum matching number M(H) of H. [Formula presented] M(H) is, among the set of proper χ(H)-colorings of H, the largest set of disjoint pairs of color classes where each pair is connected by edges of just a single color. The result is also proved for more than 2 colors and is tight up to the implied constant factor. We also study mex(n,H) when H is a cycle with a red-blue coloring of its edges, and we show that [Formula presented], which is tight.