Singularities in loop quantum cosmology

Abstract

We show that simple scalar field models can give rise to curvature singularities in the effective Friedmann dynamics of Loop Quantum Cosmology (LQC). We find singular solutions for spatially flat Friedmann-Robertson-Walker cosmologies with a canonical scalar field and a negative exponential potential, or with a phantom scalar field and a positive potential. While LQC avoids big bang or big rip type singularities, we find sudden singularities where the Hubble rate is bounded, but the Ricci curvature scalar diverges. We conclude that the effective equations of LQC are not in themselves sufficient to avoid the occurrence of singularities.

5 pages, 3 figures. v2: Comments and references added. v3: Minor additions, version to appear in PRL

References in corpus (6)

• Loop quantum cosmology of k=1 FRW models
• Loop Quantum Dynamics of the Schwarzschild Interior
• Loop quantization of spherically symmetric midi-superspaces
• The behavior of non-linear anisotropies in bouncing Bianchi I models of loop quantum cosmology
• Phantom field dynamics in loop quantum cosmology
• Effective equations for isotropic quantum cosmology including matter

Cited by in corpus (3)

• Are loop quantum cosmos never singular?
• On the quantum fate of singularities in a dark-energy dominated universe
• Physical time and other conceptual issues of QG on the example of LQC