The $*$-exponential as a covering map

We employ tools from complex analysis to construct the $*$-logarithm of a quaternionic slice regular function. Our approach enables us to achieve three main objectives: we compute the monodromy associated with the $*$-exponential; we establish sufficient conditions for the $*$-product of two $*$-exponentials to also be a $*$-exponential; we calculate the slice derivative of the $*$-exponential of a regular function.
Comment: 27 pages