2 problems

Let $\ell\ge 2$ and $n>1$, and consider rational order-$n\ell$ differential operators with $\mathbb Z_\ell$ symmetry in the preceding setup. Require that the indices at $0$ are tho…

Let $\ell\ge 2$ and let $L=\partial^\ell+a_2(z)\partial^{\ell-2}+\dots+a_\ell(z)$ be a rational differential operator invariant under $\mathbb Z_\ell$, with coefficients vanishing…