Effective equation of state and energy conditions in phantom/tachyon inflationary cosmology perturbed by quantum effects

TL;DR

This paper explores a cosmological model combining tachyon, phantom fields, and quantum effects, showing it can produce early inflation and late acceleration with variable equations of state.

Contribution

It introduces a novel model with combined phantom, tachyon, and quantum effects that naturally yields two deSitter phases and variable equations of state.

Findings

The model admits two deSitter phases for early and late universe.

Energy conditions bounds are derived for this cosmology.

The effective equation of state can change sign depending on parameters.

Abstract

We discuss the model consisting of tachyon which may have the negative kinetic energy plus scalar phantom and plus conformal quantum matter. It is demonstrated that such a model naturally admits two deSitter phases where the early universe inflation is produced by quantum effects and the late time accelerating universe is caused by phantom/tachyon. The energy conditions bounds for such cosmology are derived. It is interesting that effective equation of state may change its sign which depends from the proper choice of the combination of phantom/tachyon and quantum effects.