A Kruskal-Katona-type theorem for linear spaces
报告题目(Title)：A Kruskal-Katona-type theorem for linear spaces
报告人(Speaker)：王军 教授 （上海师范大学）
地点(Place)：腾讯会议 305 655 200
时间(Time)：2020年4月28日 15：30-16：30
邀请人(Inviter)：王恺顺
报告摘要
Roughly speaking, the “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. (A joint work with Huajun Zhang)
