Black Holes, the Generalized Uncertainty Principle and Higher Dimensions

The London Relativity and Cosmology Seminar
Bernard Carr (QMUL)
October 31st, 2012 at 16:30
Maths 103

A new way in which black holes connect macrophysics and microphysics is proposed. The Generalized Uncertainty Principle suggests corrections to the Uncertainty Principle as the energy increases towards the Planck value. It also provides a natural transition between the expressions for the Compton wavelength below the Planck mass and the black hole event horizon size above it. This suggests corrections to the the event horizon size as the black hole mass falls towards the Planck value, leading to the concept of a Generalized Event Horizon. Extrapolating this expression below the Planck mass suggests the existence of a new kind of black hole, whose size is of order its Compton wavelength. Recently it has been found that such black holes are permitted by Loop Quantum Gravity, their unusual properties deriving from the fact that they are hidden behind the throat of a wormhole, and this suggests some new kind of link between black holes and elementary particles. The form of the Generalized Uncertainty Principle in this solution leads to a new interpretation of the Hawking temperature and predicts how this should be modifed in the sub-Planckian regime, which has important implications for the formation and evaporation of black holes in the early Universe. Extrapolating these ideas to the higher-dimensional case raises the issue of whether a similar link arises in string theory.