%0 Journal Article %T Attractor-repeller pair, Morse decomposition and Lyapunov function for random dynamical systems %A Zhenxin Liu %A Shuguan Ji %A Menglong Su %J Mathematics %D 2006 %I arXiv %X In the stability theory of dynamical systems, Lyapunov functions play a fundamental role. In this paper, we study the attractor-repeller pair decomposition and Morse decomposition for compact metric space in the random setting. In contrast to [8], by introducing slightly stronger definitions of random attractor and repeller, we characterize attractor-repeller pair decompositions and Morse decompositions for random dynamical systems through the existence of Lyapunov functions. These characterizations, we think, deserve to be known widely. %U http://arxiv.org/abs/math/0606205v1