Infinitely many periodic orbits in non-exact oscillating magnetic fields   on surfaces with genus at least two for almost every low energy level
  In this paper we consider oscillating non-exact magnetic fields on surfaces with genus at least two and show that for almost every energy level $k$ below a certain value $\tau_+^*(g,\sigma)$ less than or equal to the "Ma\~n\'e critical value of the universal cover" there are infinitely many closed magnetic geodesics with energy $k$. 
Luca Asselle, Gabriele Benedetti
math.SG math.DS