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