An Optimal Control Formulation of the Blaschke–Lebesgue Theorem

AbstractThe Blaschke–Lebesgue theorem states that of all plane sets of given constant width the Reuleaux triangle has least area. The area to be minimized is a functional involving the support function and the radius of curvature of the set. The support function satisfies a second order ordinary differential equation where the radius of curvature is the control parameter. The radius of curvature of a plane set of constant width is non-negative and bounded above. Thus we can formulate and analyze the Blaschke–Lebesgue theorem as an optimal control problem