On the Floquet coefficient for bidimensional linear systems with null Lyapunov exponent

with Rafael Obaya,
in: Proceedings of Dynamic Systems and Applications 2
eds: G.S. Ladde and M. Sambandham, Atlanta, 1996.

The paper deals with some qualitative and spectral problems for a one-parameter
family of bidimensional linear systems. The derivative of the Floquet coefficient on
the absolutely continuous spectrum is calculated and the non-tangential convergence
of the Weyl m-functions in the L1-topology is shown. Proofs are based on recently
discovered properties of absolutely continuous invariant measures under the
projective flow.