GeneralizedHarmonic::Tags::Pi< Dim, Frame > Struct Template Reference

Conjugate momentum to the spacetime metric. More...

#include <Tags.hpp>

## Public Types

using type = tnsr::aa< DataVector, Dim, Frame >

## Detailed Description

### template<size_t Dim, typename Frame> struct GeneralizedHarmonic::Tags::Pi< Dim, Frame >

Conjugate momentum to the spacetime metric.

### Details

If $$\psi_{ab}$$ is the spacetime metric, and $$N$$ and $$N^i$$ are the lapse and shift respectively, then we define $$\Pi_{ab} = -\frac{1}{N} ( \partial_t \psi_{ab} + N^{i} \phi_{iab} )$$ where $$\phi_{iab}$$ is the variable defined by the tag Phi.

The documentation for this struct was generated from the following file:
• src/Evolution/Systems/GeneralizedHarmonic/Tags.hpp