On bundles that admit fiberwise hyperbolic dynamics
  This paper is devoted to rigidity of smooth bundles which are equipped with fiberwise geometric or dynamical structure. We show that the fiberwise associated sphere bundle to a bundle whose leaves are equipped with (continuously varying) metrics of negative curvature is a topologically trivial bundle when either the base space is simply connected or, more generally, when the bundle is fiber homotopically trivial. We present two very different proofs of this result: a geometric proof and a dynamical proof. We also establish a number of rigidity results for bundles which are equipped with fiberwise Anosov dynamical systems. Finally, we present a number of examples which show that our results are sharp in certain ways or illustrate necessity of various assumptions. 
F. Thomas Farrell and Andrey Gogolev
math.DS math.DG math.GT