Abstract. We describe how closed geodesics lying in a prescribed homology class on a negatively curved manifold split when lifted to a finite cover. This generalizes a result of Zelditch in the case of compact hyperbolic surfaces.
IntroductionGiven a compact manifold of negative curvature, there are geometric analogues of the Chebotarev Theorem in algebraic number theory due to Sunada [13] (cf. also Parry and Pollicott [8] for the generalization to Axiom A flows). More precisely, given a finite Galois cover of the manifold, these theorems describe the proportion of closed geodesics which lift in a prescribed way to the cover.In this geometric setting, it is also natural to consider infinite covers, and, in particular, the number of closed geodesics lying in a prescribed homology class has been studied by Katsuda and Sunada [4] Sharp [12]). In this note we shall combine these points of view, generalizing a result of Zelditch for hyperbolic Riemann surfaces [14].Let M be a compact smooth Riemannian manifold with negative curvature. Let M be a finite Galois covering of M with covering group G. For a closed geodesic γ on M , let l(γ) denote its length, γ its Frobenius class in G and [γ] its homology class in H = H 1 (M, Z).We shall examine how the closed geodesics lying in a fixed homology class α ∈ H, split when lifted to M . More precisely, for a conjugacy class C in G, we study the asymptotics ofThe problem is complicated by the fact that, in general, [γ] and γ are not independent quantities.