Observational constraints on inflection point quintessence with a cubic potential

TL;DR

This paper investigates an inflection point quintessence model with a cubic potential, deriving observational constraints and identifying conditions for both eternal and transient cosmic acceleration, with implications for cyclic universe scenarios.

Contribution

It introduces and analyzes a simple cubic potential quintessence model, providing observational constraints and exploring conditions for transient versus eternal acceleration.

Findings

Small initial scalar field values are favored by observations.

Most parameter space leads to asymptotic de Sitter expansion.

A small region allows for transient acceleration compatible with cyclic universe models.

Abstract

We examine the simplest inflection point quintessence model, with a potential given by $V(\phi) = V_0 + V_3 \phi^3$. This model can produce either asymptotic de Sitter expansion or transient acceleration, and we show that it does not correspond to either pure freezing or thawing behavior. We derive observational constraints on the initial value of the scalar field, $\phi_i$, and $V_3/V_0$ and find that small values of either $\phi_i$ or $V_3/V_0$ are favored. While most of the observationally-allowed parameter space yields asymptotic de Sitter evolution, there is a small region, corresponding to large $V_3/V_0$ and small $\phi_i$, for which the current accelerated expansion is transient. The latter behavior is potentially consistent with a cyclic universe.