title: Extreme non-linear elasticity and transformation optics.
authors.affiliation: Technical University of Denmark, Department of Mechanical Engineering, Solid Mechanics, Nils Koppels Allé, Bld. 404, DK-2800 Kgs. Lyngby, Denmark. agersborg.hansen@gmail.com
authors.forename: Allan R
authors.initials: AR
authors.lastname: Gersborg
authors.forename: Ole
authors.initials: O
authors.lastname: Sigmund