Volterra distortions, spinning strings, and cosmic defects

Cosmic strings. as topological spacetime defects, show striking resemblance to defects in solid continua: distortions, which can be classified into disclinations and dislocations, are line-like defects characterized by a delta-function-valued curvature and torsion distribution giving rise to rotational and translational holonomy. We exploit this analogy and investigate how distortions can be adapted in a systematic manner from solid-state systems to Einstein-Cartan gravity. As distortions are efficiently described within the framework of an SO(3)not superset 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 which is a natural framework for introducing the notion of distorted spacetimes. Constructing all ten possible distorted spacetimes, we recover, 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, appropriately matched to the distorted vacua are cylindrically symmetric and are interpreted as spin-polarized cosmic strings and cosmic dislocations.