Classification of ovals and hyperovals in even order

Classify all ovals and hyperovals in the projective plane PG(2, q) for even q.

Background

The paper distinguishes ovals, which are (q + 1)-arcs, from hyperovals, which are (q + 2)-arcs when q is even. Although every oval in odd characteristic is a non-singular conic, even characteristic admits many ovals and hyperovals that are not conics, including examples derived from conics and the broader family of hyperovals. A complete classification for even q is explicitly left unresolved.

References

Open problem 1. Classify all ovals and hyperovals for q even.

Arcs, Caps and Generalisations in a Finite Projective Space  (2503.06243 - Hirschfeld et al., 8 Mar 2025) in Open problem 1, Section 3, page 3