In this paper we study the decay estimates of the fourth order Schrodinger operator H = Delta 2 + V(x) on R2 with a bounded decaying potential V(x). We first deduce the asymptotic expansions of resolvent of H near zero threshold in the presence of resonances or eigenvalue, and then use them to establish the L1 - L infinity decay estimates of e-itH generated by the fourth order Schrodinger operator H. Our methods used in the decay estimates depend on Littlewood-Paley decomposition and oscillatory integral theory. Moreover, we also classify these zero resonances as the distributional solutions o...
