Cosmological Solutions of Emergent Noncommutative Gravity
Abstract
Matrix models of the YangMills type lead to an emergent gravity theory, which does not require finetuning of a cosmological constant. We find cosmological solutions of the FriedmannRobertsonWalker type. They generically have a big bounce, and an early inflationlike phase with graceful exit. The mechanism is purely geometrical; no ad hoc scalar fields are introduced. The solutions are stabilized through vacuum fluctuations and are thus compatible with quantum mechanics. This leads to a Milnelike universe after inflation, which appears to be in remarkably good agreement with observation and may provide an alternative to standard cosmology.
 Publication:

Physical Review Letters
 Pub Date:
 June 2009
 DOI:
 10.1103/PhysRevLett.102.221301
 arXiv:
 arXiv:0903.0986
 Bibcode:
 2009PhRvL.102v1301K
 Keywords:

 04.60.m;
 11.10.Nx;
 98.80.Cq;
 98.80.Qc;
 Quantum gravity;
 Noncommutative field theory;
 Particletheory and fieldtheory models of the early Universe;
 Quantum cosmology;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 4 pages, 2 figures. V2: version accepted by Phys.Rev.Lett. plus one picture