Hilton–Milner results in projective and affine spaces

Abstract

Abstract In this article, we analyse maximal sets of k-spaces, in PG(n, q) and AG(n, q) with n ≥ 2k + t + 3, that pairwise meet in at least a t-space. It is known that for both PG(n, q) and AG(n, q), the largest example is a t-pencil, i.e. the set of all k-spaces containing a fixed t-space. In this paper, we analyse the structure of the second largest maximal example in both PG(n, q) and AG(n, q).