Abstract:
A hypergraph $H=(V,E)$ has the property $B_k$ if there exists an assignment of two colors to $V$ such that each edge contains at least $k$ vertices of each color. A hypergraph is called simple if every two edges of it have at most one common vertex. We obtain a new lower bound for the minimal number of edges of $n$-uniform simple hypergraph without the property $B_k$.
Keywords:simple hypergraphs, colorings of hypergraphs, property $B$.