ScalarTensor::sgb Namespace Reference

Holds items related to Einstein-scalar-Gauss-Bonnet gravity. More...

Namespaces
namespace	CouplingFunctions
	Holds the coupling functions for Einstein-scalar-Gauss-Bonnet gravity.

Detailed Description

Holds items related to Einstein-scalar-Gauss-Bonnet gravity.

Einstein-scalar-Gauss-Bonnet is a modified gravity theory featuring a real scalar field nonminimally coupled to the metric. In this code we will follow the conventions of [156] , and write the action as

\begin{equation} S = \int_\Omega d^4 x \, \sqrt{-g} \biggl\{ \frac{\mathcal{R}}{16 \pi G} - \frac{1}{2} \bigl( \nabla_\mu \Psi \bigr) \bigl( \nabla^\mu \Psi \bigr) + \ell^2 F[\Psi] \mathcal{G} \biggr\} \end{equation}

where \(\mathcal{R}\) is the Ricci scalar, \(G\) is the Newton's, constant, \(\Psi\) is the real scalar field, \(F[\Psi]\) is its coupling function, and \(\mathcal{G}\) is the Gauss-Bonnet invariant.