Garriga Torres, JaumeVilenkin, A. (Alexander)2010-05-062010-05-0619910556-2821https://hdl.handle.net/2445/12328A covariant formalism is developed for describing perturbations on vacuum domain walls and strings. The treatment applies to arbitrary domain walls in (N+1)-dimensional flat spacetime, including the case of bubbles of a true vacuum nucleating in a false vacuum. Straight strings and planar walls in de Sitter space, as well as closed strings and walls nucleating during inflation, are also considered. Perturbations are represented by a scalar field defined on the unperturbed wall or string world sheet. In a number of interesting cases, this field has a tachyonic mass and a nonminimal coupling to the world-sheet curvature.8 p.application/pdfeng(c) The American Physical Society, 1991Teoria de camps (Física)Partícules (Física nuclear)Field theory (Physics)Particles (Nuclear physics)info:eu-repo/semantics/article507971info:eu-repo/semantics/openAccess