6533b825fe1ef96bd1282672

RESEARCH PRODUCT

Blocking sets and partial spreads in finite projective spaces

Albrecht Beutelspacher

subject

CombinatoricsDiscrete mathematicsCardinalityDifferential geometryHyperbolic geometryProjective spaceGeometry and TopologyAlgebraic geometryUpper and lower boundsSubspace topologyMathematicsProjective geometry

description

A t-blocking set in the finite projective space PG(d, q) with d≥t+1 is a set $$\mathfrak{B}$$ of points such that any (d−t)-dimensional subspace is incident with a point of $$\mathfrak{B}$$ and no t-dimensional subspace is contained in $$\mathfrak{B}$$ . It is shown that | $$\mathfrak{B}$$ |≥q t +...+1+q t−1√q and the examples of minimal cardinality are characterized. Using this result it is possible to prove upper and lower bounds for the cardinality of partial t-spreads in PG(d, q). Finally, examples of blocking sets and maximal partial spreads are given.

https://doi.org/10.1007/bf00181559