English

Effective State Metamorphosis in Semi-Classical Loop Quantum Cosmology

General Relativity and Quantum Cosmology 2009-11-11 v2 Astrophysics High Energy Physics - Theory

Abstract

Modification to the behavior of geometrical density at short scales is a key result of loop quantum cosmology, responsible for an interesting phenomenology in the very early universe. We demonstrate the way matter with arbitrary scale factor dependence in Hamiltonian incorporates this change in its effective dynamics in the loop modified phase. For generic matter, the equation of state starts varying near a critical scale factor, becomes negative below it and violates strong energy condition. This opens a new avenue to generalize various phenomenological applications in loop quantum cosmology. We show that different ways to define energy density may yield radically different results, especially for the case corresponding to classical dust. We also discuss implications for frequency dispersion induced by modification to geometric density at small scales.

Keywords

Cite

@article{arxiv.gr-qc/0502086,
  title  = {Effective State Metamorphosis in Semi-Classical Loop Quantum Cosmology},
  author = {Parampreet Singh},
  journal= {arXiv preprint arXiv:gr-qc/0502086},
  year   = {2009}
}

Comments

Revised version; includes expanded discussion of natural trans-Planckian modifications to frequency dispersion and robustness to quantization ambiguities. To appear in Class. Quant. Grav