The Sch\"utzenberger groups and maximal subgroups of tropical matrices

We classify the Sch\"utzenberger groups of the category of matrices over the tropical semiring, $M(\mathbb{T})$, in doing so, we obtain a classification for the Sch\"utzenberger groups of the semigroupoid of matrices over the finitary tropical semiring, $M(\mathbb{F}\mathbb{T})$. We then classify the maximal subgroups of the monoid of $n \times n$ matrices over the tropical semiring, $M_n(\mathbb{T})$, for all $n \in \mathbb{N}$; generalising a result in the literature and correcting an erroneous proof. We proceed to show that for some $n \in \mathbb{N}$ there exists a group which appears as a Sch\"utzenberger group of $M_n(\mathbb{T})$ but does not appear as a maximal subgroup.