# Second-order sufficient optimality conditions for the optimal control of Navier-Stokes equations

## Inst. Mathematik

In this paper sufficient optimality conditions are established for optimal control of both steady-state and evolution Navier-Stokes equations. The second-order condition requires coercivity of the Lagrange function on a suitable subspace together with first-order necessary conditions. It ensures local optimality of a reference function in a $L^s$-neighborhood, whereby the underlying analysis allows to use weaker norms than $L^\infty$.