Conditional symmetries in axisymmetric quantum cosmologies with scalar fields and the fate of the classical singularities

Journal Article · Sun May 01 04:00:00 EDT 2016 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2016/05/066· OSTI ID:22667544

Zampeli, Adamantia; Pailas, Theodoros; Terzis, Petros A.

In this paper, the classical and quantum solutions of some axisymmetric cosmologies coupled to a massless scalar field are studied in the context of minisuperspace approximation. In these models, the singular nature of the Lagrangians entails a search for possible conditional symmetries. These have been proven to be the simultaneous conformal symmetries of the supermetric and the superpotential. The quantization is performed by adopting the Dirac proposal for constrained systems, i.e. promoting the first-class constraints to operators annihilating the wave function. To further enrich the approach, we follow [1] and impose the operators related to the classical conditional symmetries on the wave function. These additional equations select particular solutions of the Wheeler-DeWitt equation. In order to gain some physical insight from the quantization of these cosmological systems, we perform a semiclassical analysis following the Bohmian approach to quantum theory. The generic result is that, in all but one model, one can find appropriate ranges of the parameters, so that the emerging semiclassical geometries are non-singular. An attempt for physical interpretation involves the study of the effective energy-momentum tensor which corresponds to an imperfect fluid.

• OSTI ID: 22667544
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 05 Vol. 2016; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AXIAL SYMMETRY
CONFORMAL INVARIANCE
ENERGY-MOMENTUM TENSOR
EQUATIONS
LAGRANGIAN FUNCTION
QUANTIZATION
QUANTUM COSMOLOGY
SCALAR FIELDS
SEMICLASSICAL APPROXIMATION
SINGULARITY
WAVE FUNCTIONS