A remark on Brans-Dicke dust cosmological solutions with negative $\omega$

TL;DR

This paper investigates Brans-Dicke dust cosmological solutions with negative omega, revealing scenarios with initial subluminal expansion, inflation, and potential links to string theory, relevant to supernova observations, age, and structure formation.

Contribution

It demonstrates that negative omega Brans-Dicke solutions can exhibit inflationary phases and connects these findings to string effective models, expanding understanding of alternative cosmologies.

Findings

Solutions show initial subluminal expansion followed by inflation

Potential compatibility with supernova data and age constraints

Connections to string effective models are discussed

Abstract

Analysing the Brans-Dicke solutions for the dust phase, we show that, for negative values of $\omega$, they contain scenarios that display an initial subluminal expansion followed by an inflationary phase. We discuss these solutions with respect to the results of the observation of high redshif supernova as well as the age problem and structure formation. We stablish possible connections of these solutions with those emerging from string effective models.