Asymptotically Static Universe

TL;DR

This paper proposes a cosmological model where the universe approaches a static state asymptotically, achieved through a balance of matter, a negative cosmological constant, and a generalized quintom scalar field, which is classically stable.

Contribution

It introduces a novel asymptotic static universe scenario using a generalized quintom model with a negative cosmological constant, expanding the possibilities of late-time cosmic evolution.

Findings

The universe can asymptotically approach a static state.

The model remains classically stable.

Balance between matter, negative cosmological constant, and scalar fields is key.

Abstract

We consider a cosmology in which the final stage of the Universe is neither accelerating nor decelerating, but approaches an asymptotic state where the scale factor becomes a constant value. In order to achieve this, we first bring in a scale factor with the desired property and then determine the details of the energy contents as a result of the cosmological evolution equations. We show that such a scenario can be realized if we introduce a generalized quintom model which consists of a scalar field and a phantom with a {\it negative} cosmological constant term. The standard cold dark matter with $w_m=0$ is also introduced. This is possible basically due to the balance between the matter and the {\it negative} cosmological constant which tend to attract and scalar field and phantom which repel in the asymptotic region. The stability analysis shows that this asymptotic solution is classically stable.