6533b7d6fe1ef96bd126714c

RESEARCH PRODUCT

On the type of partial t-spreads in finite projective spaces

Franco EugeniAlbrecht Beutelspacher

subject

Discrete mathematicsCombinatoricsHyperplaneDimension (vector space)Projective spaceDiscrete Mathematics and CombinatoricsType (model theory)Element (category theory)Upper and lower boundsLinear subspaceSubspace topologyMathematicsTheoretical Computer Science

description

AbstractA partial t-spread in a projective space P is a set of mutually skew t-dimensional subspaces of P. In this paper, we deal with the question, how many elements of a partial spread L can be contained in a given d-dimensional subspace of P. Our main results run as follows. If any d-dimensional subspace of P contains at least one element of L, then the dimension of P has the upper bound d−1+(d/t). The same conclusion holds, if no d-dimensional subspace contains precisely one element of L. If any d-dimensional subspace has the same number m>0 of elements of L, then L is necessarily a total t-spread. Finally, the ‘type’ of the so-called geometric t-spreads is determined explicitely.

10.1016/0012-365x(85)90109-8http://dx.doi.org/10.1016/0012-365X(85)90109-8