报告方式：腾讯会议 ID：905 127 519 会议密码：210119
邀请人：许宝刚教授
摘要：A Kruskal-Katona-type problem for a graph G concerned here is to describe each subset of vertices of G that has minimal neighborhood respect to its size. We establish a Kruskal-Katona-type theorem for the q-Kneser graph,whose vertex set consists of all k-dimensional subspaces of an n-dimensional linear space over a q-element field, two subspaces are adjacent if they have the trivial intersection. It includes as a special case the Erdos--Ko--Rado theorem for intersecting families in finite vector spaces and yields a short proof of the Hilton-Milner theorem for nontrivial intersecting families in finite vector spaces.