Almost reducibility of linear difference systems from a spectral point   of view
  We prove that, under some conditions, a linear nonautonomous difference system is Bylov's almost reducible to a diagonal one whose terms are contained in the Sacker and Sell spectrum of the original system.   We also provide an example of the concept of diagonally significant system, recently introduced by P\"otzche. This example plays an essential role in the demonstration of our results. 
Alvaro Casta\~neda and Gonzalo Robledo
math.CA