The circular loop equation of a cosmic string with time-varying tension
arXiv:0801.2808 · doi:10.1142/S0217732308026340
Abstract
The equation of circular loops of cosmic string with time-dependent tension is studied in the Minkowski spacetime and Robertson-Walker universe. We find that, in the case where the tension depends on some power of the cosmic time, cosmic string loops with time-varying tension should not collapse to form a black hole if the power is lower than a critical value.
8 pages, 3 figures. accepted by Modern Physics Letters A