Minimal multiplicity of prime closed orbits without additional assumptions
Determine whether, without any extra geometric or dynamical conditions on M, a Reeb flow on the boundary of a smooth star-shaped domain in R^{2n} must have more than one prime closed orbit, or more than two prime closed orbits if the flow is non-degenerate.
References
For instance, without extra conditions on M, it is not even known that there must be more than one prime orbit or more than two if the flow is non-degenerate.
— Closed Orbits of Dynamically Convex Reeb Flows: Towards the HZ- and Multiplicity Conjectures
(2410.13093 - Cineli et al., 16 Oct 2024) in Section 1.1 (Introduction)