Complex field as inflaton and quintessence

TL;DR

This paper explores how a single complex scalar field can unify the descriptions of early inflation and current accelerated expansion, potentially eliminating the need for separate quintessence or a cosmological constant.

Contribution

It demonstrates that a complex scalar field can account for both inflationary and late-time acceleration phases in cosmology, offering a unified model without a cosmological constant.

Findings

Complex field models can produce two inflationary stages and oscillatory regimes.

Such models can explain current acceleration without a cosmological constant.

The universe may avoid eternal acceleration if driven by a complex field.

Abstract

We investigate cosmology with complex scalar field. It is shown that such models can describe two stages of inflation and the oscillatory regime. Thus we don't need both quintessence and $\Lambda$-term. It is enough to have single complex field to obtain both inflation and present accelerated universe. If the present accelerated expansion was created by the complex field then universe must escape eternal acceleration. Besides, we will show that cosmological equations with complex field admit stationary solution without any cosmological constant.