Selected Topics in PlanckScale Physics
Abstract
We review a few topics in Planckscale physics, with emphasis on possible manifestations in relatively low energy. The selected topics include quantum fluctuations of spacetime, their cumulative effects, uncertainties in energy momentum measurements, and low energy quantumgravity phenomenology. The focus is on quantumgravityinduced uncertainties in some observable quantities. We consider four possible ways to probe Planckscale physics experimentally: (i) looking for energydependent spreads in the arrival time of photons of the same energy from GRBs; (ii) examining spacetime fluctuationinduced phase incoherence of light from extragalactic sources; (iii) detecting spacetime foam with laserbased interferometry techniques; (iv) understanding the threshold anomalies in high energy cosmic ray and gamma ray events. Some other experiments are briefly discussed. We show how some physics behind black holes, simple clocks, simple computers, and the holographic principle is related to Planckscale physics. We also discuss a formulation of the Dirac equation as a difference equation on a discrete Planckscale spacetime lattice, and a possible interplay between Planckscale and Hubblescale physics encoded in the cosmological constant (dark energy).
 Publication:

Modern Physics Letters A
 Pub Date:
 2003
 DOI:
 10.1142/S0217732303010934
 arXiv:
 arXiv:grqc/0305019
 Bibcode:
 2003MPLA...18.1073N
 Keywords:

 04.60.m;
 04.70.Dy;
 04.80.Nn;
 98.70.Sa;
 03.67.Lx;
 Quantum gravity;
 Quantum aspects of black holes evaporation thermodynamics;
 Gravitational wave detectors and experiments;
 Cosmic rays;
 Quantum computation;
 General Relativity and Quantum Cosmology;
 Astrophysics;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 31 pages, 1 figure