Line data    Source code

       1            0 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : #pragma once
       5              : 
       6              : #include "DataStructures/DataBox/Tag.hpp"
       7              : #include "DataStructures/Tensor/Tensor.hpp"
       8              : #include "Evolution/Systems/CurvedScalarWave/Tags.hpp"
       9              : #include "Evolution/Systems/ScalarTensor/Tags.hpp"
      10              : #include "PointwiseFunctions/GeneralRelativity/Tags.hpp"
      11              : #include "PointwiseFunctions/ScalarTensor/ScalarGaussBonnet/CouplingParameters.hpp"
      12              : #include "PointwiseFunctions/ScalarTensor/ScalarGaussBonnet/Tags.hpp"
      13              : #include "PointwiseFunctions/ScalarTensor/SourceTags.hpp"
      14              : #include "Time/Tags/Time.hpp"
      15              : #include "Utilities/Gsl.hpp"
      16              : 
      17              : namespace ScalarTensor {
      18              : /// @{
      19              : /*!
      20              :  * \brief Computes the source term given by the coupling of the scalar to
      21              :  * curvature.
      22              :  *
      23              :  * \details For a scalar field with mass parameter $ m_\Psi $,
      24              :  * the wave equation takes the form
      25              :  * \begin{align}
      26              :  *   \Box \Psi = \mathcal{S} ~,
      27              :  * \end{align}
      28              :  *
      29              :  * where the source is given by
      30              :  * \begin{align}
      31              :  *   \mathcal{S} \equiv m^2_\Psi \Psi - f'(\Psi) \mathcal{G}~,
      32              :  * \end{align}
      33              :  * where
      34              :  * \begin{align}
      35              :  *   \mathcal{G} \equiv 8 (E_{ab} E^{ab} - B_{ab} B^{ab}) ~,
      36              :  * \end{align}
      37              :  * is the Gauss-Bonnet scalar and the coupling function is given by
      38              :  * \begin{align}
      39              :  *   f(\Psi) \equiv \lambda \Psi
      40              :  *      + \dfrac{1}{16} \left( \eta \Psi^2 + 2 \zeta \Psi^4 \right) ~,
      41              :  * \end{align}
      42              :  * Here the Gauss-Bonnet scalar (in vacuum) is given in terms of the electric
      43              :  * ($ E_{ab} $) and magnetic ($ B_{ab} $) parts of the Weyl scalar.
      44              :  *
      45              :  */
      46            1 : void gauss_bonnet_scalar_source(
      47              :     gsl::not_null<Scalar<DataVector>*> scalar_source,
      48              :     const Scalar<DataVector>& weyl_electric_scalar,
      49              :     const Scalar<DataVector>& weyl_magnetic_scalar,
      50              :     const Scalar<DataVector>& psi,
      51              :     const CouplingParameterOptions& coupling_parameters, double mass_psi,
      52              :     std::pair<double, double> start_and_ramp_times, double time);
      53              : 
      54            1 : Scalar<DataVector> gauss_bonnet_scalar_source(
      55              :     const Scalar<DataVector>& weyl_electric_scalar,
      56              :     const Scalar<DataVector>& weyl_magnetic_scalar,
      57              :     const Scalar<DataVector>& psi,
      58              :     const CouplingParameterOptions& coupling_parameters, double mass_psi,
      59              :     std::pair<double, double> start_and_ramp_times, double time);
      60              : /// @}
      61              : 
      62              : /*!
      63              :  * \brief Multiplies by the coupling function.
      64              :  *
      65              :  * \details Multiply by the first derivative of the coupling function given by
      66              :  * \begin{align}
      67              :  *   f(\Psi) \equiv
      68              :  *      + \dfrac{1}{16} \left( 4 \lambda \Psi + 2 \eta \Psi^2 + \zeta \Psi^4
      69              :  * \right) ~.
      70              :  * \end{align}
      71              :  *
      72              :  */
      73            1 : void multiply_by_negative_deriv_of_coupling_func(
      74              :     gsl::not_null<Scalar<DataVector>*> scalar_source,
      75              :     const Scalar<DataVector>& psi,
      76              :     const CouplingParameterOptions& coupling_parameters,
      77              :     std::pair<double, double> start_and_ramp_times, double time);
      78              : 
      79              : /*!
      80              :  * \brief Multiplies by the coupling function.
      81              :  *
      82              :  * \details Multiply by the second derivative of the coupling function given by
      83              :  * \begin{align}
      84              :  *   f(\Psi) \equiv
      85              :  *      + \dfrac{1}{16} \left( 4 \lambda \Psi + 2 \eta \Psi^2 + \zeta \Psi^4
      86              :  * \right) ~.
      87              :  * \end{align}
      88              :  *
      89              :  */
      90            1 : void multiply_by_negative_second_deriv_of_coupling_func(
      91              :     gsl::not_null<Scalar<DataVector>*> scalar_source,
      92              :     const Scalar<DataVector>& psi,
      93              :     const CouplingParameterOptions& coupling_parameters,
      94              :     std::pair<double, double> start_and_ramp_times, double time);
      95              : 
      96              : namespace Tags {
      97              : /*!
      98              :  * \copydoc ScalarTensor::gauss_bonnet_scalar_source
      99              :  */
     100            1 : struct ScalarSourceCompute : ScalarSource, db::ComputeTag {
     101            0 :   using argument_tags = tmpl::list<
     102              :       gr::Tags::WeylElectricScalar<DataVector>,
     103              :       gr::Tags::WeylMagneticScalar<DataVector>, CurvedScalarWave::Tags::Psi,
     104              :       ScalarTensor::Tags::CouplingParameters, ScalarTensor::Tags::ScalarMass,
     105              :       ScalarTensor::Tags::RampUpParameters, ::Tags::Time>;
     106            0 :   using return_type = Scalar<DataVector>;
     107            0 :   static constexpr void (*function)(
     108              :       const gsl::not_null<Scalar<DataVector>*> /* scalar_source */,
     109              :       const Scalar<DataVector>& /* weyl_electric_scalar */,
     110              :       const Scalar<DataVector>& /* weyl_magnetic_scalar */,
     111              :       const Scalar<DataVector>& /* psi */,
     112              :       const CouplingParameterOptions& /* coupling_parameters */,
     113              :       const double /* mass_psi */,
     114              :       const std::pair<double, double> /* start_and_ramp_times */,
     115              :       const double /* time */) = &gauss_bonnet_scalar_source;
     116            0 :   using base = ScalarSource;
     117              : };
     118              : }  // namespace Tags
     119              : 
     120              : }  // namespace ScalarTensor