Journal article

Publication year: 1991

Pages: 99-114

Journal: Geometriae Dedicata

Volume number: 39

Issue number: 1

ISSN: 0046-5755

Publisher: Springer

Abstract: 

Let P = PG(2t + 1, q) denote the projective space of order q and of dimension 2t + 1 greater-than-or-equal-to 3. A set L of lines of P is called a blockade if it fulfills the following two conditions.

1. Every (t + 1)-dimensional subspace of P contains at least one line of L.

2. If x is the intersecting point of two lines of L, then every (t + 1)-dimensional subspace of P through x contains at least one line of l through x.

The most interesting examples of these blockades are the geometric spreads and the line sets of Baer subspaces of P. In our main result we shall classify the blockades under the additional property that there exists a t-dimensional subspace T of P such that each point of T is incident property that there exists a t-dimensional subspace T of P such that each point of T is incident with at most one line of L. As a corollary we determine the blockades of minimal cardinality.

Harvard Citation style: UEBERBERG, J. (1991) BLOCKADES AND BAER SUBSPACES IN FINITE PROJECTIVE SPACES, Geometriae Dedicata, 39(1), pp. 99-114

APA Citation style: UEBERBERG, J. (1991). BLOCKADES AND BAER SUBSPACES IN FINITE PROJECTIVE SPACES. Geometriae Dedicata. 39(1), 99-114.