Brane world cosmologies with varying speed of light - art. no. 125011

We study cosmologies in the Randall-Sundrum (RS) models, incorporating the possibility of a time-varying speed of light and Newton's constant. The cos mologies with varying speed of light (VSL) were proposed by Moffat and by A lbrecht and Magueijo as an alternative to inflation for solving cosmologica l problems. We consider the case in which the speed of light varies with ti me after the radion or the scale of the extra dimension has been stabilized . We elaborate on the conditions under which the flatness problem and the c osmological constant problem can be resolved. We find that the RS models ar e more restrictive about possible desirable VSL cosmological models than st andard general relativity. Particularly, VSL cosmologies may provide us wit h a possible mechanism for bringing quantum corrections to fine-tuned brane tensions after the SUSY breaking under control.