Fermion Doubling in Loop Quantum Gravity
General Relativity and Quantum Cosmology
2015-07-07 v1 High Energy Physics - Lattice
Abstract
In this paper, we show that the Hamiltonian approach to loop quantum gravity has a fermion doubling problem. To obtain this result, we couple loop quantum gravity to a free massless scalar and a chiral fermion field, gauge fixing the many fingered time gauge invariance by interpreting the scalar field as a physical clock. We expand around a quantum gravity state based on a regular lattice and consider the limit where the bare cosmological constant is large but the fermonic excitations have energies low in Planck units. We then make the case for identifying the energy spectrum in this approximation with that of a model of lattice fermion theory which is known to double.
Keywords
Cite
@article{arxiv.1507.01232,
title = {Fermion Doubling in Loop Quantum Gravity},
author = {Jacob Barnett and Lee Smolin},
journal= {arXiv preprint arXiv:1507.01232},
year = {2015}
}