Relative Turán density of ascending uniform hypergraph paths

Determine the relative Turán density \(\mathfrak{o}(P^{r}_2)\) of the ascending \(r\)-uniform path of length two for every \(r\ge 3\), and in particular determine whether \(\mathfrak{o}(P^{3}_2)=1/2\).

Background

The definition of relative Turán density extends to hypergraphs. The paper cites known lower bounds for the ascending rr-uniform path of length two and notes a quantitative improvement for r=4r=4. The exact value remains unresolved for general rr, with the case r=3r=3 singled out as a specific question; the authors also mention the analogous problem for longer paths.

References

Problem 4.4. Determine o(PT)) for all r ≥ 3. In particular, is (P23)) = = true? Of course, one may also ask the same question for longer paths.

Relative Turán densities of ordered graphs  (2501.06853 - Reiher et al., 12 Jan 2025) in Problem 4.4, Section 4 (Concluding Remarks)