Title: Determining rough first order perturbations of the polyharmonic operator,
Abstract: We show that the knowledge of Dirichlet to Neumann map for rough $A$ and $q$
in $(-\Delta)^m +A\cdot D +q$ for $m \geq 2$ for a bounded domain in
$\mathbb{R}^n$, $n \geq 3$ determines $A$ and $q$ uniquely. The unique
identifiability is proved using property of products of functions in Sobolev
spaces and constructing complex geometrical optics solutions with sufficient
decay of remainder terms.