English

Quantum gravity as a Fermi liquid

High Energy Physics - Theory 2008-12-18 v2 Superconductivity General Relativity and Quantum Cosmology

Abstract

We present a reformulation of loop quantum gravity with a cosmological constant and no matter as a Fermi-liquid theory. When the topological sector is deformed and large gauge symmetry is broken, we show that the Chern-Simons state reduces to Jacobson's degenerate sector describing 1+1 dimensional propagating fermions with nonlocal interactions. The Hamiltonian admits a dual description which we realize in the simple BCS model of superconductivity. On one hand, Cooper pairs are interpreted as wormhole correlations at the de Sitter horizon; their number yields the de Sitter entropy. On the other hand, BCS is mapped into a deformed conformal field theory reproducing the structure of quantum spin networks. When area measurements are performed, Cooper-pair insertions are activated on those edges of the spin network intersecting the given area, thus providing a description of quantum measurements in terms of excitations of a Fermi sea to superconducting levels. The cosmological constant problem is naturally addressed as a nonperturbative mass-gap effect of the true Fermi-liquid vacuum.

Keywords

Cite

@article{arxiv.0807.0225,
  title  = {Quantum gravity as a Fermi liquid},
  author = {Stephon H. S. Alexander and Gianluca Calcagni},
  journal= {arXiv preprint arXiv:0807.0225},
  year   = {2008}
}

Comments

45 pages, 1 figure; v2: discussion improved, version accepted by Found. Phys

R2 v1 2026-06-21T10:56:32.771Z