Journal of the
Korean Mathematical Society JKMS

Let $E$ be a real, non-degenerate, indefinite inner product space with dim $E\ge 3$. It is shown that any bijection of $E$ which preserves the light cones is an affine map.

Keywords: Minkowski space-time, Lorentz group, causality, indefinite inner product spaces, light cones, neutral automorphisms

MSC numbers: 46C20, 47B50, 83A05