In this paper, we establish first the resonance identity for non-contractible homologically visible prime closed geodesics on Finsler $n$-dimensional real projective space $(\mathbb{ R}P^n,F)$ when there exist only finitely many distinct non-contractible closed geodesics on $(\mathbb{ R}P^n,F)$, where the integer $n\geq2$. Then as an application of this resonance identity, we prove the existence of at least two distinct non-contractible closed geodesics on $\mathbb{ R}P^{ n}$ with a bumpy and irreversible Finsler metric. Together with two previous results on bumpy and reversible Finsler metrics in \cite{ DLX2015} and \cite{ Tai2016}, it yields that every $\mathbb{ R}P^{ n}$ with a bumpy Finsler metric possesses at least two distinct non-contractible closed geodesics.
Categories: math.DS math.DG math.SG