| The objective of this thesis is three fold. First, we consider linear stochastic partial differential equations (SPDEs) of divergence and nondivergence forms. In chapter 4, we study {dollar}Lsb{lcub}p{rcub}{dollar} -regularity for generalized solutions of equations with discontinuous coefficients. In chapter 5, we develop an {dollar}Lsb{lcub}p{rcub}{dollar}-theory of SPDEs of divergence form with continuous coefficients. Second, in chapter 6, the Cauchy problem for one-dimensional nonlinear SPDEs is studied. Third, we study numerical approximation of SPDEs. In chapter 7, we develop an {dollar}Lsb2{dollar}-theory for discrete stochastic evolution equations, in particular, stochastic partial difference equations obtained by discretizing SPDEs of divergence form. Chapter 8 concerns the finite difference approximation of SPDEs. We study the difference between the solutions of SPDEs and their discretizations using {dollar}Lsb2{dollar}-theory and {dollar}Lsb{lcub}p{rcub}{dollar}-theory. Error estimates and the rates of convergence are obtained. |