My work covers algebraic combinatorics, extremal combinatorics, finite geometry, spectral graph theory, Boolean analysis, semidefinite programming, intersecting families, and association schemes.


Please note that sometimes there are significant differences between the preprint and the journal version of a paper.
  1. With Yuval Filmus: Boolean degree 1 functions on some classical association schemes. Journal of Combinatorial Theory A, 2019. Preprint.
  2. With Andries E. Brouwer, Sebastian M. Cioabă, and Matt McGinnis: The smallest eigenvalues of Hamming graphs, Johnson graphs and other distance-regular graphs with classical parameters. Journal of Combinatorial Theory B, 2018. Preprint.
  3. With the University of Regina Discrete Mathematics Research Group (6 coauthors): Ovoids of Generalized Quadrangles of Order (q,q^2−q) and Delsarte Cocliques in Related Strongly Regular Graphs. Journal of Combinatorial Designs, 2018. Preprint.
  4. With Klaus Metsch and Bernhard Mühlherr: An EKR theorem for finite buildings of type Dl. Journal of Algebraic Combinatorics, 2018.
  5. With Karen Meagher: Manickam-Miklós-Singhi Conjectures on Partial Geometries. Designs, Codes and Cryptography, 2018. Preprint.
  6. With the University of Regina Discrete Mathematics Research Group (6 coauthors): Infection in Hypergraphs. Discrete Applied Mathematics, 2018. Preprint.
  7. 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, 2018. Preprint.
  8. With Klaus Metsch: Large {0, 1,...,t}-Cliques in Dual Polar Graphs. Journal of Combinatorial Theory A, 2018. Preprint.
  9. With Anurag Bishnoi: The non-existence of distance-2 ovoids in H(4)^D. Contributions to Discrete Mathematics, 2017. Preprint.
  10. A Switching for Strongly Regular Collinearity Graphs From Polar Spaces. Journal of Algebraic Combinatorics, 2017. Preprint.
  11. 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.
  12. A Note on the Manickam-Miklós-Singhi Conjecture for Vector Spaces, European Journal of Combinatorics, 2016. Preprint.
  13. Cross-intersecting Erdős-Ko-Rado Sets in Dual Polar Graphs, Electronic Journal of Combinatorics, 2015.
  14. 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.
  15. 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.
  16. With Klaus Metsch: On the Maximum Size of Erdős-Ko-Rado Sets in H(2d+1, q^2), Designs, Codes and Cryptography, 2014. Preprint.



Karen Meagher (3), Klaus Metsch (3), Ryan Bergen (2), Yuval Filmus (2), Alison Purdy (2), Boting Yang (2), John Bamberg, Anurag Bishnoi, Andries E. Brouwer, Sebastian M. Cioabă, Jan De Beule, Shaun Fallat, Adam Gorr, Daniel Heinlein, Sam Jaques, Andrey Kupavskii, Matt McGinnis, Bernhard Mühlherr, Deepak Rajendraprasad, Peter Sin, Thilo Weinert, Qing Xiang, Guanglong Yu.

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


Universiteit Gent and Vakgroep Wiskunde.

Hebrew University of Jerusalem and Einstein Institute.

University of Regina and Department of Mathematics and Statistics.

Justus-Liebig-Universität Gießen and Mathematisches Institut.