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/TypeAliases.hpp"
       8              : #include "Evolution/Systems/ForceFree/Tags.hpp"
       9              : #include "PointwiseFunctions/GeneralRelativity/TagsDeclarations.hpp"
      10              : #include "Utilities/TMPL.hpp"
      11              : 
      12              : /// \cond
      13              : namespace Tags {
      14              : template <typename Tag>
      15              : struct Normalized;
      16              : }  // namespace Tags
      17              : namespace gsl {
      18              : template <typename T>
      19              : class not_null;
      20              : }  // namespace gsl
      21              : /// \endcond
      22              : 
      23              : namespace ForceFree {
      24            1 : namespace Tags {
      25              : /*!
      26              :  * \brief Compute the largest characteristic speed of the GRFFE system with
      27              :  * divergence cleaning.
      28              :  *
      29              :  * Wave speeds of the fast modes of the GRFFE system are the speed of light.
      30              :  *
      31              :  * \f{align*}
      32              :  *  \lambda_\pm = \beta^i\beta_i \pm \alpha
      33              :  * \f}
      34              :  *
      35              :  * where \f$\alpha\f$ is the lapse and \f$\beta^i\f$ is the shift. Therefore the
      36              :  * largest characteristic speed is \f$\lambda_\text{max} =
      37              :  * \sqrt{\beta_i\beta^i}+\alpha\f$.
      38              :  */
      39            1 : struct LargestCharacteristicSpeedCompute : LargestCharacteristicSpeed,
      40              :                                            db::ComputeTag {
      41            0 :   using argument_tags =
      42              :       tmpl::list<gr::Tags::Lapse<DataVector>, gr::Tags::Shift<DataVector, 3>,
      43              :                  gr::Tags::SpatialMetric<DataVector, 3>>;
      44            0 :   using return_type = double;
      45            0 :   using base = LargestCharacteristicSpeed;
      46            0 :   static void function(gsl::not_null<double*> speed,
      47              :                        const Scalar<DataVector>& lapse,
      48              :                        const tnsr::I<DataVector, 3>& shift,
      49              :                        const tnsr::ii<DataVector, 3>& spatial_metric);
      50              : };
      51              : 
      52              : }  // namespace Tags
      53              : }  // namespace ForceFree