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/Tensor/Tensor.hpp"
       7              : #include "Utilities/Gsl.hpp"
       8              : 
       9              : namespace gr {
      10              : /// @{
      11              : /*!
      12              :  * \brief Computes the momentum constraint in vacuum.
      13              :  *
      14              :  * \details The momentum constraint in vacuum GR reads (cf. Eq. (2.96) in
      15              :  * \cite BaumgarteShapiro)
      16              :  * \begin{equation}
      17              :  *   \mathcal{M}_i = D_j {K^j}_i - D_i K = 0,
      18              :  * \end{equation}
      19              :  * where $D_i$ is the covariant derivative with respect to the spatial metric,
      20              :  * $K_{ij}$ is the extrinsic curvature and $K$ is its trace.
      21              :  */
      22              : template <typename DataType, size_t SpatialDim, typename Frame>
      23            1 : void momentum_constraint_in_vacuum(
      24              :     gsl::not_null<tnsr::i<DataType, SpatialDim, Frame>*> momentum_constraint,
      25              :     const tnsr::ijj<DataType, SpatialDim, Frame>& d_extrinsic_curvature,
      26              :     const tnsr::i<DataType, SpatialDim, Frame>& d_trace_extrinsic_curvature,
      27              :     const tnsr::II<DataType, SpatialDim, Frame>& inverse_spatial_metric);
      28              : 
      29              : template <typename DataType, size_t SpatialDim, typename Frame>
      30            1 : tnsr::i<DataType, SpatialDim, Frame> momentum_constraint_in_vacuum(
      31              :     const tnsr::ijj<DataType, SpatialDim, Frame>& d_extrinsic_curvature,
      32              :     const tnsr::i<DataType, SpatialDim, Frame>& d_trace_extrinsic_curvature,
      33              :     const tnsr::II<DataType, SpatialDim, Frame>& inverse_spatial_metric);
      34              : /// @}
      35              : 
      36              : }  // namespace gr