Publications

Most of my publications are about extremal combinatorics in finite geometries which I often solve with help from algebraic combinatorics. Among other things I am interested in ovoids, spreads, tight sets, EKR sets, MMS sets, some Ramsey numbers, distance-regular graphs, network codes and generalized polygons. I try to have descriptive titles which might be more helpful than my random list of keywords.

Accepted/Published

Please note that sometimes there are significant differences between the preprint and the journal version of a paper.
  1. With Klaus Metsch and Bernhard Mühlherr: An EKR theorem for finite buildings of type Dl. Journal of Algebraic Combinatorics, Accepted.
  2. With Peter Sin and Qing Xiang: New Bounds for Partial Spreads of H(2d-1, q^2) and Partial Ovoids of the Ree-Tits Octagon. Journal of Combinatorial Theory A, Accepted. Preprint.
  3. With Karen Meagher: Miklós-Manickam-Singhi Conjectures on Partial Geometries. Designs, Codes and Cryptography, Accepted. Preprint.
  4. With Klaus Metsch: Large {0, 1,...,t}-Cliques in Dual Polar Graphs. Journal of Combinatorial Theory A, Accepted. Preprint.
  5. A Switching for Strongly Regular Collinearity Graphs From Polar Spaces. Journal of Algebraic Combinatorics, Accepted. Preprint.
  6. With Anurag Bishnoi: The non-existence of distance-2 ovoids in H(4)^D. Contributions to Discrete Mathematics, Accepted. Preprint.
  7. With John Bamberg and Jan De Beule: New non-existence proofs for ovoids of Hermitian polar spaces and hyperbolic quadrics, Annals of Combinatorics, 2017. Preprint.
  8. A Note on the Manickam-Miklós-Singhi Conjecture for Vector Spaces, European Journal of Combinatorics, 2016. Preprint.
  9. Cross-intersecting Erdős-Ko-Rado Sets in Dual Polar Graphs, Electronic Journal of Combinatorics, 2015.
  10. A new upper bound for constant distance codes of generators on hermitian polar spaces of type H(2d − 1, q^2), Journal of Geometry, 2014. Preprint.
  11. A Characterisation of the Natural Embedding of the Split Cayley Hexagon in PG(6,q) by Intersection Numbers in Finite Projective Spaces of Arbitrary Dimension. Discrete Mathematics, 2014. Preprint.
  12. With Klaus Metsch: On the Maximum Size of Erdős-Ko-Rado Sets in H(2d+1, q^2), Designs, Codes and Cryptography, 2014. Preprint.

Submitted/Preprint

Work In Progress (titles will usually change, incomplete)

Colloquium/Conference Talks

(Please ask for slides of any of my talks if you want them. I stopped uploading most of them.)

Seminar/Invited Session Talks

Contributed Talks

Theses


The Hebrew University of Jerusalem and Einstein Institute.

University of Regina and Department of Mathematics and Statistics.

Justus-Liebig-Universität Gießen and Mathematisches Institut.