Thermal duality and gravitational collapse Michael Hewitt Computing, Digital Forensics and Cybersecurity Canterbury Christ Church University 17 February 2015 Abstract Thermal duality is a relationship between the behaviour of het- erotic string models of the E(8)xE(8) or SO(32) types at inversely related temperatures, a variant of T duality in the Euclidean regime. This duality would have consequences for the nature of the Hagedorn transition in these string models. We propose that the vacuum admits a family of deformations in situations where there are closed surfaces of constant area but high radial acceleration (a string regularized ver- sion of a Penrose trapped surface), such as would be formed in situ- ations of extreme gravitational collapse. This would allow a radical resolution of the firewall paradox by allowing quantum effects to sig- nificantly modify the spacetime geometry around a collapsed object. A string bremsstrahlung process would convert the kinetic energy of infalling matter in extreme gravitational collapse to form a region of the deformed vacuum, which would be equivalent to forming a high temperature string phase. A heuristic criterion for the conversion pro- cess is presented, relating Newtonian gravity to the string tension, suggesting an upper limit to the strength of the gravitational interac- tion. This conversion process might have observable consequences for charged particles falling into a rotating collapsed object by producing high energy particles via a variant of the Penrose process. PACS numbers: 11.25.Sq, 11.25.Mj, 04.70Dy. 1 Black holes and discrete symmetries The family of classical black hole solutions is parameterised by mass, charge (standard model gauge charges) and angular momentum. Consider the ef- fect of discrete symmetries on them. Whereas C and P are satisfactory T is not, as time reversed black holes are not (usually) allowed. This represents a radical violation of T and by extension CPT symmetry, and because of 1 arXiv:1504.04830v1 [hep-th] 19 Apr 2015