Magnetic corepresentations

Let \(\mathcal{M}\) be a magnetic group that admits a unitary halving subgroup \(\mathcal{G}\). The symmetry characterisation of a linear-space quantity \(\mathbfit{w}\) with respect to \(\mathcal{M}\) is most properly done using Wigner's corepresentation theory in which the antiunitarity of the elements in \(\mathcal{M} \setminus \mathcal{G}\) is respected. This is treated in QSym² by an implementation of the character theory of magnetic groups developed by Newmarch and Golding.

A brief summary of this method will be added to this site in the future.