ABSTRACT We study evolutionary equations in exponentially weighted ‐spaces as introduced by Picard in 2009. First, for a given evolutionary equation, we explicitly describe the ‐adjoint system, which turns out to describe a system backwards in time. We prove well‐posedness for the ‐adjoint system. We then apply the obtained duality to introduce and study notions of null controllability for evolutionary equations.
Buchinger et al. (Sun,) studied this question.