Almost commensurability of 3-dimensional Anosov flows (Q2376606)

Two flows are called commensurable if they admit finite coverings by topologically equivalent flows. Two flows \(\phi,\psi\) on manifolds \(M,N\) are called almost commensurable if there exists a finite collection \(\Gamma\) (respectively, \(G\)) of periodic orbits of \(\phi\) (respectively, of \(\psi\)) such that \(\phi|_{M\setminus \Gamma}\) is commensurable to \(\psi|_{N\setminus G}\). The author shows that all suspensions of automorphisms of the 2-torus and all geodesic flows on unit tangent bundles to hyperbolic 2-orbifolds are pairwise almost commensurable.