Maximilian P. Wollner

Polyconvexity for incompressible inversion-symmetric energies of Valanis-Landel type

{Let $\lambda_i = \nu_i(F)$ denote the three singular values of the deformation gradient $F \in {\rm GL}^+(3)$.} We consider the family of incompressible isotropic energies $ W_\psi(F)=\sum_i \psi\left(|\!\log\lambda_i|\right)$ with $\psi:[0,\infty)\mapsto\mathbb{R}$. Set $g(s)=\psi\left({\rm arcosh}\frac{s}{2}\right)$...