Abstract:
Starting from an heuristic approach to the semiclassical limit in loop quantum gravity, the construction of effective Hamiltonians describing Planck length corrections to the propagation of photons and spin 1/2 fermions, leading to modified energy-momentum relations, is summarized. Assuming the existence of a privileged reference frame, we also review the determination of stringent bounds upon the parameters labelling such corrections, based upon already existing experimental data, which are found to be from five to nine orders of magnitude below the expected values.
Note:
  • 10 pages, no figures, ws-procs 975x65.cls, extended version of the talk given at the Tenth Marcel Grossmann Meeting, Rio de Janeiro, July 20-26, 2003
  • talk: Rio de Janeiro 2003/07/20
  • quantum gravity
  • loop space
  • effective Hamiltonian
  • approximation: semiclassical
  • dispersion relation: deformation
  • cosmic background radiation
  • spin: 1/2