We show for k⩾ 2 that if q⩾ 3 and n⩾ 2k+ 1, or q= 2 and n⩾ 2k+ 2, then any intersecting
family F of k-subspaces of an n-dimensional vector space over GF (q) with⋂ F∈ FF= 0 has …

Let n and t be positive integers with t< n, and let q be a prime power. A partial (t− 1)-spread
of PG (n− 1, q) is a set of (t− 1)-dimensional subspaces of PG (n− 1, q) that are pairwise …

The problems we study in this thesis arise in computer science, extremal set theory and
quantum computing. The first common feature of these problems is that each can be …

In this survey recent results about q-analogues of some classical theorems in extremal set
theory are collected. They are related to determining the chromatic number of the q …

We study network maximum distance separable (MDS) codes, which are a class of network
error-correcting codes whose distance attains the Singleton-type bound. The minimum field …

Let Z ps be the residue class ring of integers modulo ps, where p is a prime number and s is
a positive integer. We study subspaces and Grassmann graphs for Z ps n. A Grassmann …

After completing my master's degree with a thesis on codes arising from the incidence
matrices of finite projective spaces and their substructures, I started in October 2010 as a …

Minimal multicast networks are fascinating and efficient combinatorial objects, where the
removal of a single link makes it impossible for all receivers to obtain all messages. We …

This thesis focuses on the interplay of extremal combinatorics and finite geometry.
Combinatorics is concerned with discrete (and usually finite) objects. Extremal …

The original Erdős-Ko-Rado problem has inspired much research. It started as a study on
sets of pairwise intersecting k-subsets in an n-set, then it gave rise to research on sets of …