Positivity of the top Lyapunov exponent for cocycles on semisimple Lie   groups over hyperbolic bases
  A theorem of Viana says that almost all cocycles over any hyperbolic system have nonvanishing Lyapunov exponents. In this note we extend this result to cocycles on any noncompact classical semisimple Lie group. 
Mario Bessa, Jairo Bochi, Michel Cambrainha, Carlos Matheus, Paulo   Varandas and Disheng Xu
math.DS