English

On the Constant that Fixes the Area Spectrum in Canonical Quantum Gravity

General Relativity and Quantum Cosmology 2010-04-06 v1

Abstract

The formula for the area eigenvalues that was obtained by many authors within the approach known as loop quantum gravity states that each edge of a spin network contributes an area proportional to sqrt{j(j+1)} times Planck length squared to any surface it transversely intersects. However, some confusion exists in the literature as to a value of the proportionality coefficient. The purpose of this rather technical note is to fix this coefficient. We present a calculation which shows that in a sector of quantum theory based on the connection A=Gamma-gamma*K, where Gamma is the spin connection compatible with the triad field, K is the extrinsic curvature and gamma is Immirzi parameter, the value of the multiplicative factor is 8*pi*gamma. In other words, each edge of a spin network contributes an area 8*pi*gamma*l_p^2*sqrt{j(j+1)} to any surface it transversely intersects.

Cite

@article{arxiv.gr-qc/9709058,
  title  = {On the Constant that Fixes the Area Spectrum in Canonical Quantum Gravity},
  author = {Kirill Krasnov},
  journal= {arXiv preprint arXiv:gr-qc/9709058},
  year   = {2010}
}

Comments

Revtex, 7 pages, no figures