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 hamiltonian constraint in vacuum.
      13             :  *
      14             :  * \details The hamiltonian constraint in vacuum GR reads (cf. Eq. (2.90) in
      15             :  * \cite BaumgarteShapiro)
      16             :  * \begin{equation}
      17             :  *   \mathcal{H} = R + K^2 - K_{ij}K^{ij} = 0,
      18             :  * \end{equation}
      19             :  * where $R$ is the spatial Ricci scalar, $K_{ij}$ is the extrinsic curvature
      20             :  * and $K$ is its trace.
      21             :  */
      22             : template <typename DataType, size_t SpatialDim, typename Frame>
      23           1 : void hamiltonian_constraint_in_vacuum(
      24             :     gsl::not_null<Scalar<DataType>*> hamiltonian_constraint,
      25             :     const Scalar<DataType>& ricci_scalar,
      26             :     const Scalar<DataType>& trace_extrinsic_curvature,
      27             :     const tnsr::II<DataType, SpatialDim, Frame>& inverse_spatial_metric,
      28             :     const tnsr::ii<DataType, SpatialDim, Frame>& extrinsic_curvature);
      29             : 
      30             : template <typename DataType, size_t SpatialDim, typename Frame>
      31           1 : Scalar<DataType> hamiltonian_constraint_in_vacuum(
      32             :     const Scalar<DataType>& ricci_scalar,
      33             :     const Scalar<DataType>& trace_extrinsic_curvature,
      34             :     const tnsr::II<DataType, SpatialDim, Frame>& inverse_spatial_metric,
      35             :     const tnsr::ii<DataType, SpatialDim, Frame>& extrinsic_curvature);
      36             : /// @}
      37             : }  // namespace gr