In condensed-matter physics, a Nambu-Goldstone mode is a particular low energy deformation of an ordered phase arising from a symmetry of the ground state. Examples are acoustic phonons and spin waves. In this paper, I use the fact that an isometry is a symmetry of the stretching energy of a shell to derive a set of low energy Goldstone-like deformations. This new approach to understanding the small deformations of shells is then used to revisit the problem of a pinched cylinder and used to study a pinched cone.
C.D. Santangelo, “Nambu-Goldstone modes and diffuse deformations in elastic shells,” to appear in Soft Matter (2013). [ARXIV]