Characteristic restrictions for nonclassical good pseudo-ovoids

Determine whether an odd-characteristic good pseudo-ovoid in PG(4n − 1, q) that is neither classical nor of Kantor–Knuth type necessarily has q equal to a power of 3.

Background

The paper classifies good pseudo-ovoids in odd characteristic into several cases, including classical, Kantor–Knuth, and a further Veronese-surface case. Known examples outside the first two types occur for q = 3h, and the authors ask whether this observed characteristic restriction is necessary.

References

Open problem 12. If the pseudo-ovoid O of PG(4n − 1, q), q odd, is good, but neither classical nor of Kantor-Knuth type, is q necessarily a power of 3?

Arcs, Caps and Generalisations in a Finite Projective Space  (2503.06243 - Hirschfeld et al., 8 Mar 2025) in Open problem 12, Section 8.6, page 9