Dynamics of a Generalized Cosmological Scalar-Tensor Theory

TL;DR

This paper explores a generalized scalar-tensor cosmological model where the cosmological term depends on a scalar field and its derivative, providing analytic solutions and discussing implications for dark matter and the cosmological constant.

Contribution

It introduces a novel generalized scalar-tensor theory with a dynamic cosmological term and finds analytic solutions, linking it to higher-dimensional theories and observational data.

Findings

Analytic solutions for scale factor, scalar field, and cosmological term.

Models align with recent observational data.

Potential relevance to dark matter and cosmological constant problems.

Abstract

A generalized scalar-tensor theory is investigated whose cosmological term depends on both a scalar field and its time derivative. A correspondence with solutions of five-dimensional Space-Time-Matter theory is noted. Analytic solutions are found for the scale factor, scalar field and cosmological term. Models with free parameters of order unity are consistent with recent observational data and could be relevant to both the dark-matter and cosmological-"constant" problems.