Dirac Fields in Loop Quantum Gravity and Big Bang Nucleosynthesis
Abstract
Big Bang nucleosynthesis requires a fine balance between equations of state for photons and relativistic fermions. Several corrections to equation of state parameters arise from classical and quantum physics, which are derived here from a canonical perspective. In particular, loop quantum gravity allows one to compute quantum gravity corrections for Maxwell and Dirac fields. Although the classical actions are very different, quantum corrections to the equation of state are remarkably similar. To lowest order, these corrections take the form of an overall expansion-dependent multiplicative factor in the total density. We use these results, along with the predictions of Big Bang nucleosynthesis, to place bounds on these corrections.
Cite
@article{arxiv.0710.5734,
title = {Dirac Fields in Loop Quantum Gravity and Big Bang Nucleosynthesis},
author = {Martin Bojowald and Rupam Das and Robert J. Scherrer},
journal= {arXiv preprint arXiv:0710.5734},
year = {2008}
}
Comments
15 pages, 2 figures; v2: new discussion of relevance of quantum gravity corrections (Sec. II) and new estimates (Sec. V)