Extremal mappings of finite distortion and the Radon–Riesz property

Abstract

We consider Sobolev mappings f ∈ W 1;q(Ω; C), 1 < q < ∞, between planar domains Ω ⊂ ℂ. We analyse the Radon–Riesz property for polyconvex functionals of the form (Formula presented) and show that under certain criteria, which hold in important cases, weak convergence in Wloc1;q.(Ω) of (for instance) a minimising sequence can be improved to strong convergence. This finds important applications in the minimisation problems for mappings of finite distortion and the Lp and Exp-Teichmüller theories.