Strings and the gauge theory of spacetime defects

摘要

We present a new topological invariant to describe space-time defects which is closely related to the torsion tensor in a Riemann-Cartan manifold. By virtue of the topological current theory and phi-mapping method, we show that there must exist multistring objects generated from the zero points of the phi-mapping. These strings are topologically quantized. The topological quantum numbers are the winding numbers described by the Hopf indices and the Brouwer degrees of the phi-mapping. References: 27