Electronic Journal of Differential Equations, Vol. 2019 (2019), No. 86, pp. 1-19. Title: Multiple positive solutions for Schrodinger-Poisson systems involving concave-convex nonlinearities Author: Haining Fan (China Univ. of Mining and Technology, Xuzhou, China) Abstract: In this article, we study the existence of multiple positive solutions for Schrodinger-Poisson systems involving concave-convex nonlinearities and sign-changing weight potentials. With the help of Nehari manifold and Ljusternik-Schnirelmann category theory, we investigate how the coefficient g(x) of the critical nonlinearity affects the number of positive solutions. Furthermore, we obtain a relationship between the number of positive solutions and the topology of the global maximum set of g. Submitted July 24, 2018. Published July 16, 2019. Math Subject Classifications: 35A15, 35B33, 35J62. Key Words: Multiple positive solutions; Schrodinger-Poisson system; critical Sobolev exponent; Nehari manifold; Ljusternik-Schnirelmann category.