Properties of singularities in (phantom) dark energy universe

TL;DR

This paper classifies and analyzes future singularities in dark energy-dominated universes, especially with phantom energy, exploring their properties, stability, and quantum correction effects.

Contribution

It provides a classification of finite-time singularities, models their occurrence with specific equations of state, and examines quantum effects on singularity behavior.

Findings

Existence of a stable phantom dark energy attractor.

Construction of a Big Rip scenario with dark matter coupling.

Quantum corrections can moderate singularities.

Abstract

The properties of future singularities are investigated in the universe dominated by dark energy including the phantom-type fluid. We classify the finite-time singularities into four classes and explicitly present the models which give rise to these singularities by assuming the form of the equation of state of dark energy. We show the existence of a stable fixed point with an equation of state $w<-1$ and numerically confirm that this is actually a late-time attractor in the phantom-dominated universe. We also construct a phantom dark energy scenario coupled to dark matter that reproduces singular behaviors of the Big Rip type for the energy density and the curvature of the universe. The effect of quantum corrections coming from conformal anomaly can be important when the curvature grows large, which typically moderates the finite-time singularities.