A Supplement to the Classification of Flat Homogeneous Spaces of Signature (m,2)

Abstract

Duncan and Ihrig (1993) gave a classification of the flat homogeneous spaces of metric signature (m,2), provided that a certain condition on the development image of these spaces holds. In this note we show that this condition can be dropped, so that Duncan and Ihrig's classification is in fact the full classification for signature (m,2).Comment: shortened, one reference added, fixed typo