Shadows of 3-uniform hypergraphs under a minimum degree condition

Autor: Füredi, Zoltán, Zhao, Yi
Rok vydání: 2021
Předmět:
Druh dokumentu: Working Paper
Popis: We prove a minimum degree version of the Kruskal--Katona theorem: given $d\ge 1/4$ and a triple system $F$ on $n$ vertices with minimum degree at least $d\binom n2$, we obtain asymptotically tight lower bounds for the size of its shadow. Equivalently, for $t\ge n/2-1$, we asymptotically determine the minimum size of a graph on $n$ vertices, in which every vertex is contained in at least $\binom t2$ triangles. This can be viewed as a variant of the Rademacher--Tur\'an problem.
Databáze: arXiv