On the multiplicity of closed geodesics on Finsler spheres with irrationally elliptic closed geodesics

Abstract

If all prime closed geodesics on $(S^n,F)$ with an irreversible Finsler metric $F$ are irrationally elliptic, there exist either exactly $2\left[\frac{n+1}{2}\right]$ or infinitely many distinct closed geodesics. As an application, we show the existence of three distinct closed geodesics on bumpy Finsler $(S^3,F)$ if any prime closed geodesic has non-zero Morse index.

12 pages. To appear in SCIENCE CHINA Mathematics. arXiv admin note: text overlap with arXiv:1504.00245; text overlap with arXiv:0909.3566 by other authors