On Simply Laminated Microstructure in Martensitic Crystals Bo Li Department of Mathematics University of California at Los Angeles and Department of Mathematics University of Maryland at College Park Abstract One of the most commonly observed microstructure in martensitic crystals such as metals and alloys is a simply laminated microstructure. Such a microstructure can be represented by a sequence of deformations whose gradients take values of two compatible constant matrices on parallel bands with vanishing band size. In this talk, we are concerned with the variational problem of an elastic energy functional for such a microstructure. To model the martensitic phase transformation that leads to microstructure, we assume that the energy density is rotationally invariant and is minimized on multiple energy wells. We impose a Dirichlet boundary condition that is compatible with a simply laminated microstructure. We first show the uniqueness of a simply laminated microstructure in terms of Young measures generated by gradients of energy minimizing sequences of deformations. We then present a theory of stability for the simply laminated microstructure, and discuss its applications to numerical analysis on the finite element approximations of such a microstructure. This talk summarizes a series of joint works with Mitchell Luskin, and a recent joint work with Kaushik Bhattacharya and Mitchell Luskin. Request for preprints and reprints address to the speaker at bli@math.ucla.edu This information can be found at http://www.math.utah.edu/research/