arXiv subjects
Publications and source records attributed to Fabio Scardigli.
Recently much work has been done in lowering the Planck threshold of quantum gravitational effects (sub-millimeter dimension(s), Horava-Witten fifth dimension, strings or branes low energy effects, etc.). Working in the framework of 4-dim gravity, with semi-classical considerations based on Hawking evaporation of planckian micro-black holes, I shall show here as quantum gravity effects could occur also near GUT energies.
We review versions of the Generalized Uncertainty Principle (GUP) obtained in string theory and in gedanken experiments carried out in Quantum Gravity. We show how a GUP can be derived from a measure gedanken experiment involving micro-black holes at the Planck scale of spacetime. The model uses only Heisenberg principle and Schwarzschild radius and it is independent from particular versions of Quantum Gravity.
The spacetime foam structure is reviewed briefly (topogical fluctuations and virtual black hole possibility; equation of state of the foam). A model of space foam at the surface of the event horizon is introduced. The model is applied to the calculus of the number of states of a black hole, of its entropy and of other thermodynamical properties. A formula for the number of microholes on the surface of the event horizon is derived. Thermodynamical properties of the event horizon are extended to thermodynamical properties of the space. On the basis of the previous results, the possibility of micro black holes creation by the Unruh Effect is investigated.