Sudden Singularities in Brans-Dicke Cosmology and its Generalisations

TL;DR

This paper demonstrates that finite-time sudden singularities respecting energy conditions can occur in Brans-Dicke and scalar-tensor cosmologies, including higher-order and self-interacting scalar field scenarios.

Contribution

It explicitly constructs examples of sudden singularities in Brans-Dicke and generalized scalar-tensor theories, extending previous understanding of singularities in alternative gravity models.

Findings

Sudden singularities can occur at finite times in scalar-tensor cosmologies.

Higher-order and self-interacting scalar field models also admit such singularities.

These singularities respect classical energy conditions.

Abstract

We show that cosmological sudden singularities that respect the energy conditions can occur at finite times in Brans-Dicke and more general scalar-tensor theories of gravity. We construct these explicitly in the Friedmann universes. Higher-order versions of these singularities are also possible, including those that arise with when scalar fields have a self-interaction potential of power-law form.7 pages, no figures