template<typename DataType, size_t Dim, typename OutputCoordsTag, typename VelocityTag, typename Fr = Frame::Inertial>
struct grmhd::ValenciaDivClean::Tags::QuadrupoleMomentDerivativeCompute< DataType, Dim, OutputCoordsTag, VelocityTag, Fr >
Compute tag for the first time derivative of the quadrupole moment.
Compute item for the first time derivative of the quadrupole moment, using \(\tilde{D} (v^i x^j + x^i v^j)\) (equation 23 of [164]), with \(\tilde{D}=\sqrt{\gamma}\rho W\), \(W\) being the Lorentz factor, \(\gamma\) being the determinant of the spatial metric, \(x\) the coordinates in Frame Fr, and \(v\) the corresponding spatial velocity.