Appears in collection : Jean-Morlet Chair : Hyperbolicity and dimension / Chaire Jean-Morlet : Hyperbolicité et dimension

We consider the one-parameter families of transfer operators for geodesic flows on negatively curved manifolds. We show that the spectra of the generators have some "band structure" parallel to the imaginary axis. As a special case of "semi-classical" transfer operator, we see that the eigenvalues concentrate around the imaginary axis with some gap on the both sides.