Keszegh–Pálvölgyi directed-hypergraph 2-coloring conjecture with multiple head-vertices
Prove that every directed hypergraph in which each hyperedge has more tail-vertices than head-vertices, every hyperedge has size at least three, and any two hyperedges intersecting in exactly one vertex have that common vertex as a head-vertex in at least one of the two hyperedges admits a proper 2-coloring, without restricting hyperedges to have exactly one head-vertex.
References
While we proved that Conjecture \ref{conjecture} is true for directed hypergraphs with all hyperedges having size at least three and exactly one head-vertex, the conjecture is still open in the case a hyperedge can have more head-vertices.
— Coloring one-headed directed hypergraphs
(2503.00189 - Szabó, 28 Feb 2025) in Section Open questions