Marked length spectra of Gromov hyperbolic space

Abstract

Let $(X,d)$, $(Y, d')$ be two roughly geodesically complete Gromov hyperbolic spaces under comparable isometric actions of $\Gamma$. Assume that the limit set $\Lambda \Gamma=\partial X\partial Y$. If spaces $X$ and $Y$ have the same asymptotic marked length spectrum, meaning that $$\lim_{{l_{d}([\gamma])\to \infty}}\frac{l_d(\gamma)}{l_{d'}(\gamma)}=1.$$ Then $(X,d)$ and $(Y,d')$ are $\Gamma$-equivariantly roughly isometric.