Multiplicative Invariant Fields of Dimension \le 6

Akinari Hoshi, Ming-chang Kang, Aiichi Yamasaki

The finite subgroups of $G{L}_4(\mathbf{Z})$ are classified up to conjugation in \cite{BBNWZ}; in particular, there exist $710$ non-conjugate finite groups in $G{L}_4(\mathbf{Z})$. Each finite…