  Since J. L. Lagrange initiated in 1760 the study of minimal surfaces of
Euclidean 3-space, minimal surfaces in real space forms have been studied
extensively by many mathematicians during the last two and half centuries. In
contrast, so far very few results on minimal Lorentz surfaces in indefinite
space forms are known. Hence, in this paper we investigate minimal Lorentz
surfaces in arbitrary indefinite space forms. As a consequence, we obtain
several classification results for minimal Lorentz surfaces in indefinite space
forms. In particular, we completely classify all minimal Lorentz surfaces in a
pseudo-Euclidean space $\mathbb E^m_s$ with arbitrary dimension $m$ and
arbitrary index $s$.
