THE (2+2)-SIGNATURE AND THE (1+1)-MATRIX-BRANE

Abstract

We discuss different aspects of the (2+2)-signature from the point of view of the quatl theory. In particular, we compare two alternative approaches to such a spacetime signature, namely the (1+1)-matrix-brane and the (2+2)-target spacetime of a string. This analysis also reveals hidden discrete symmetries of the (2+2)-brane action associated with the (2+2)-dimensional sector of a (2+10)-dimensional target background.