title: Inequality between size and angular momentum for bodies.
abstract: A universal inequality that bounds the angular momentum of a body by the square of its size is presented and heuristic physical arguments are given to support it. We prove a version of this inequality, as consequence of the Einstein equations, for the case of rotating axially symmetric, constant density, bodies. Finally, the physical relevance of this result is discussed.
authors.affiliation: Facultad de Matemática, Astronomía y Física, FaMAF, Universidad Nacional de Córdoba, Instituto de Física Enrique Gaviola, IFEG, CONICET, Ciudad Universitaria (5000) Córdoba, Argentina.
authors.forename: Sergio
authors.initials: S
authors.lastname: Dain