VOLTERRA DISTORTIONS, SPINNING STRINGS, AND COSMIC DEFECTS

Cosmic strings. as topological spacetime defects, show striking resemb lance to defects in solid continua: distortions, which can be classifi ed into disclinations and dislocations, are line-like defects characte rized by a delta-function-valued curvature and torsion distribution gi ving rise to rotational and translational holonomy. We exploit this an alogy and investigate how distortions can be adapted in a systematic m anner from solid-state systems to Einstein-Cartan gravity. As distorti ons are efficiently described within the framework of an SO(3)not supe rset of T(3) gauge theory of solid continua with line defects, we are led in a straightforward way to a Poincare gauge approach to gravity w hich is a natural framework for introducing the notion of distorted sp acetimes. Constructing all ten possible distorted spacetimes, we recov er, inter alia, the well known exterior spacetime of a spin-polarized cosmic string as a special case of such a geometry. In a second step, we search For matter distributions which, in Einstein-Cartan gravity, act as sources of distorted spacetimes. The resulting solutions, appro priately matched to the distorted vacua are cylindrically symmetric an d are interpreted as spin-polarized cosmic strings and cosmic dislocat ions.