We investigate the historical roots of the field of combinatorics on words. They comprise applications and interpretations in algebra, geometry and combinatorial enumeration. The...
3 We define four families of geometries with as point graph the graph — or its complement — of all elliptic 4 hyperplanes of a given parabolic quadric in any finite 6-dimensi...
We give a construction to obtain a t-design from a t-wise balanced design. More precisely, given a positive integer k and a t(v, {k1, k2, . . . , ks}, λ) design D, with with all ...
We give a characterization of the root shadow spaces of buildings whose types correspond to Dynkin diagrams. The results generalize earlier geometric point-line characterizations ...
Abstract. Given a simplicial hyperplane arrangement H and a subspace arrangement A embedded in H, we define a simplicial complex ∆A,H as the subdivision of the link of A induced...
Let A and B be hypergraphs with a common vertex set V . In a (p, q, A ∪ B) Bart-Moe game, the players take turns selecting previously unclaimed vertices of V . The game ends whe...
Dan Hefetz, Michael Krivelevich, Tibor Szabó...