Title: On Quaternionic Tori and their Moduli Spaces,
Abstract: Quaternionic tori are defined as quotients of the skew field $\mathbb{H}$ of
quaternions by rank-4 lattices. Using slice regular functions, these tori are
endowed with natural structures of quaternionic manifolds (in fact quaternionic
curves), and a fundamental region in a $12$-dimensional real subspace is then
constructed to classify them up to biregular diffeomorphisms. The points of the
moduli space correspond to suitable \emph{special} bases of rank-4 lattices,
which are studied with respect to the action of the group $GL(4, \mathbb{Z})$,
and up to biregular diffeomeorphisms. All tori with a non trivial group of
biregular automorphisms - and all possible groups of their biregular
automorphisms - are then identified, and recognized to correspond to five
different subsets of boundary points of the moduli space.