// Calculates U_mu^dagger(x-\hat{mu})V(x-\hat{\mu})
Eigen::MatrixXcd GaugeField::backward_uv(const Eigen::VectorXcd &v,
const ssize_t t,
const int spatial_ind,
const int direction) const {
int down_ind = idown[spatial_ind][direction];
return (tslices.at(t))[down_ind][direction].adjoint() * v.segment(3 * down_ind, 3);
}
// Calculates U_mu(x)V(x+\hat{\mu})
Eigen::MatrixXcd GaugeField::forward_uv(const Eigen::VectorXcd &v,
const ssize_t t,
const int spatial_ind,
const int direction) const {
int up_ind = iup[spatial_ind][direction];
return (tslices.at(t))[spatial_ind][direction] * v.segment(3 * up_ind, 3);
}