title: Conical defects in growing sheets.
abstract: A growing or shrinking disc will adopt a conical shape, its intrinsic geometry characterized by a surplus angle phi(e) at the apex. If growth is slow, the cone will find its equilibrium. Whereas this is trivial if phi(e)<or=0, the disc can fold into one of a discrete infinite number of states if phi(e)>0. We construct these states in the regime where bending dominates and determine their energies and how stress is distributed in them. For each state a critical value of phi(e) is identified beyond which the cone touches itself. Before this occurs, all states are stable; the ground state has twofold symmetry.
authors.affiliation: Laboratoire de Physique Statistique de l'Ecole Normale Supérieure (UMR 8550), associé aux Universités Paris 6 et Paris 7 et au CNRS, 24, rue Lhomond, 75005 Paris, France.
authors.forename: Martin Michael
authors.initials: MM
authors.lastname: Müller
authors.forename: Martine Ben
authors.initials: MB
authors.lastname: Amar
authors.forename: Jemal
authors.initials: J
authors.lastname: Guven