Quantum effects and superquintessence in the new age of precision cosmology

TL;DR

This paper explores how quantum effects can resolve singularities in superquintessence models, making them viable for describing the universe's accelerated expansion consistent with recent supernova observations.

Contribution

It demonstrates that including quantum counterterms in conformally coupled superquintessence models removes anisotropic singularities, extending their viability in cosmological modeling.

Findings

Quantum corrections eliminate anisotropic singularities.

Superquintessence models can describe superaccelerated universe phases.

Models remain consistent with current observational data.

Abstract

Recent observations of Type Ia supernova at high redshifts establish that the dark energy component of the universe has (a probably constant) ratio between pressure and energy density $w=p/\rho=-1.02(^{+0.13}_{-0.19})$. The conventional quintessence models for dark energy are restricted to the range $-1\le w < 0$, with the cosmological constant corresponding to $w=-1$. Conformally coupled quintessence models are the simplest ones compatible with the marginally allowed superaccelerated regime ($w<-1$). However, they are known to be plagued with anisotropic singularities. We argue here that the extension of the classical approach to the semiclassical one, with the inclusion of quantum counterterms necessary to ensure the renormalization, can eliminate the anisotropic singularities preserving the isotropic behavior of conformally coupled superquintessence models. Hence, besides of having other interesting properties, they are consistent candidates to describe the superaccelerated phases of the universe compatible with the present experimental data.