Expansions of the real field by discrete subgroups of Gl${}_n(\mathbb{C})$

Philipp Hieronymi, Erik Walsberg, Samantha Xu

Let $\Gamma$ be an infinite discrete subgroup of Gl${}_n(\mathbb{C})$. Then either $(\mathbb{R},<,+,\cdot ,\Gamma )$ is interdefinable with $(\mathbb{R},<,+,\cdot ,{\lambda }^{\mathbb{Z}})$ for some…