Formal monodromy
= Formal monodromy
{title2=$M_f=e^{2\pi i\Theta}$}
An unramified formal <fundamental matrix> $\widehat Y=\widehat G(\lambda)\lambda^\Theta e^{Q(\lambda)}$ acquires the right factor $e^{2\pi i\Theta}$ on a positive turn of the <logarithm> branch. This is <formal monodromy>. It can be nontrivial even when the true equation has an entire <fundamental matrix> and trivial actual <monodromy>, because <Stokes matrices> compensate for it.