2 problems

Existence conjecture. For every energy level $k\in(U_*,c)$, there exists a contractible or non-contractible closed $(g,\sigma,U)$-geodesic.

Let $(g,b)$ be a magnetic system on $S^2$ that is resonant at zero speed. A sequence of speeds … should exist such that, for every $n\in\mathds{N}$, there are infinitely many perio…