Thermal duality and gravitational collapse in heterotic string theories.

The thermal duality of E(8) x E(8) and SO(32) heterotic string theories may underpin a mechanism that would convert the kinetic en-ergy of infalling matter during gravitational collapse to form a region of a hot string phase that would expel gravitational gradients. This phase would be the continuation of a Ginzburg-Landau like supercon-ductor in the Euclidean regime. In this scenario, there would be no event horizon or singularity produced in gravitational collapse. Solu-tions are presented for excitations of the string vacuum that may form during gravitational collapse and drive the transition to the hot phase. The proposed mechanism is developed here for the case of approxi-mately spherical gravitational collapse in 4 uncompactified spacetime dimensions. A way to reconcile the large entropy apparently produced in this process with quantum mechanics is briefly discussed. In this scenario, astrophysical objects such as stellar or galactic cores which have undergone extreme gravitational collapse would currently be sites of an on-going conversion process to shells of this high temperature phase. The relationship of this proposal to the ‘firewall paradox ’ is noted