Black hole formation and spacetime fluctuations in two dimensional dilaton gravity and complementarity
Abstract
We study black hole formation in a model of two dimensional dilaton gravity and 24 massless scalar fields with a boundary. We find the most general boundary condition consistent with perfect reflection of matter and the constraints. We show that in the semiclassical approximation and for the generic value of a parameter which characterizes the boundary conditions, the boundary starts receding to infinity at the speed of light whenever the total energy of the incoming matter flux exceeds a certain critical value. This is also the critical energy which marks the onset of black hole formation. We then compute the quantum fluctuations of the boundary and of the rescaled scalar curvature and show that as soon as the incoming energy exceeds this critical value, and asymptotic observer using normal time resolutions will always measure large quantum fluctuations of spacetime near the horizon, even though the freely falling observer does not. This is an aspect of black hole complementarity relating directly to quantum gravity effects.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 January 1994
 Bibcode:
 1994STIN...9522739D
 Keywords:

 Black Holes (Astronomy);
 Boundary Conditions;
 Gravitation;
 SpaceTime Functions;
 Curvature;
 Shock Waves;
 Astrophysics