Local cosmic strings in Brans-Dicke theory with a cosmological constant

TL;DR

This paper demonstrates that, unlike in Brans-Dicke theory without a cosmological constant, Vilenkin's equation of state for static cosmic strings becomes consistent when a cosmological constant is included, and provides the full solution for such strings.

Contribution

It shows the compatibility of Vilenkin's equation of state with Brans-Dicke theory when a cosmological constant is present and derives the complete nonlinear solution for cosmic strings in this context.

Findings

Vilenkin's equation of state is consistent with Brans-Dicke theory with a cosmological constant

Full nonlinear solutions for cosmic strings with a cosmological constant are obtained

The inconsistency without a cosmological constant is addressed and resolved

Abstract

It is known that Vilenkin's phenomenological equation of state for static straight cosmic strings is inconsistent with Brans-Dicke theory. We will prove that, in the presence of a cosmological constant, this equation of state is consistent with Brans-Dicke theory. The general solution of the full nonlinear field equations, representing the interior of a cosmic string with a cosmological constant is also presented.