Electronic Journal of Differential Equations, Vol. 2012 (2012), No. 49, pp. 1-19. Title: Evolution equations in generalized Stepanov-like pseudo almost automorphic spaces Author: Toka Diagana (Howard Univ., Washington, DC, USA) Abstract: In this article, first we introduce and study the concept of $\mathbb{S}_{\gamma}^p$-pseudo almost automorphy (or generalized Stepanov-like pseudo almost automorphy), which is more general than the notion of Stepanov-like pseudo almost automorphy due to Diagana. We next study the existence of solutions to some classes of nonautonomous differential equations of Sobolev type in $\mathbb{S}_{\gamma}^p$-pseudo almost automorphic spaces. To illustrate our abstract result, we will study the existence and uniqueness of a pseudo almost automorphic solution to the heat equation with a negative time-dependent diffusion coefficient. Submitted February 1, 2012. Published March 27, 2012. Math Subject Classifications: 58D25, 58D25, 43A60, 35B15, 42A75, 37L05. Key Words: Pseudo almost automorphic; Stepanov-like; almost automorphic.