cosmic string

A hypothetical line-like defect in the fabric of spacetime, in the form of an infinite line or a closed loop, arising as a consequence of Grand Unified Theories of elementary particles. The thickness of cosmic strings would be 10-31 metres and their mass about ten million solar masses per light year. These tube-like configurations of energy may have arisen in the early universe and they could have played an important role in the formation of galaxy clusters. There is no observational evidence yet for the existence of cosmic strings.