We give a new and complete proof of the following theorem, discovered by
Detlef Laugwitz: (forward) complete and connected finite dimensional Finsler
manifolds admitting a proper homothety are Minkowski vector spaces. More
precisely, we show that under these hypotheses the Finsler manifold is
isometric to the tangent Minkowski vector space of the fixed point of the
homothety via the exponential map of the canonical spray of the Finsler
manifold.Comment: 13 page
