SpECTRE
v2023.05.16

Auxiliary variable which is analytically the spatial derivative of the natural log of the lapse. More...
#include <Tags.hpp>
Public Types  
using  type = tnsr::i< DataType, Dim, Frame > 
Auxiliary variable which is analytically the spatial derivative of the natural log of the lapse.
If \( \alpha \) is the lapse, then we define \(A_i = \partial_i ln(\alpha) = \frac{\partial_i \alpha}{\alpha}\).