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