Constraining scalar-tensor quintessence by cosmic clocks

TL;DR

This paper uses cosmic clocks like galaxy clusters and quasars to constrain scalar-tensor quintessence models, providing new bounds on their parameters by analyzing lookback times across different redshifts.

Contribution

It introduces a method to constrain non-minimally coupled scalar-tensor models using cosmic clocks and exact solutions of Einstein's equations.

Findings

Constraints on scalar-tensor model parameters derived from galaxy cluster data.

Discussion on the high redshift time-scale problem and alternative cosmic clocks.

Identification of confidence regions for cosmological parameters based on lookback time measurements.

Abstract

Scalar-tensor quintessence models can be constrained by identifying suitable cosmic clocks which allow to select confidence regions for cosmological parameters. In particular, we constrain the characterizing parameters of non-minimally coupled scalar-tensor cosmological models which admit exact solutions of the Einstein field equations. Lookback time to galaxy clusters at low intermediate, and high redshifts is considered. The high redshift time-scale problem is also discussed in order to select other cosmic clocks such as quasars.