Line data    Source code

       1            1 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : /// \file
       5              : /// Documents the `sgb` namespace
       6              : 
       7              : #pragma once
       8              : 
       9              : /*!
      10              :  * \brief Holds items related to Einstein-scalar-Gauss-Bonnet gravity.
      11              :  *
      12              :  * Einstein-scalar-Gauss-Bonnet is a modified gravity theory featuring a real
      13              :  * scalar field nonminimally coupled to the metric. In this code we will follow
      14              :  * the conventions of \cite Nee2024bur , and write the action as
      15              :  * \begin{equation}
      16              :  *  S = \int_\Omega d^4 x \, \sqrt{-g} \biggl\{ \frac{\mathcal{R}}{16 \pi G}
      17              :  *    - \frac{1}{2} \bigl( \nabla_\mu \Psi \bigr) \bigl( \nabla^\mu \Psi \bigr)
      18              :  *    + \ell^2 F[\Psi] \mathcal{G} \biggr\}
      19              :  * \end{equation}
      20              :  * where \f$\mathcal{R}\f$ is the Ricci scalar, \f$G\f$ is the Newton's,
      21              :  * constant, \f$\Psi\f$ is the real scalar field, \f$F[\Psi]\f$ is its coupling
      22              :  * function, and \f$\mathcal{G}\f$ is the Gauss-Bonnet invariant.
      23              :  */
      24              : namespace ScalarTensor::sgb {}