MATRIX ERNST-POTENTIALS FOR EINSTEIN-MAXWELL-DILATON-AXION WITH MULTIPLE VECTOR-FIELDS

We show that the Einstein-Maxwell-dilaton-axion system with multiple v ector fields (bosonic sector of the D = 4, N = 4 supergravity) restric ted to spacetimes possessing a non-null Killing vector field admits a concise representation in terms of the Ernst-type matrix valued potent ials. A constructive derivation of the SWIP solutions is given and a c olliding waves counterpart of the DARN-NUT solution is obtained. SU(m, m) chiral representation of the two-dimensionally reduced system is de rived and the corresponding Kramer-Neugebauer-type map is presented. ( C) 1997 Published by Elsevier Science B.V.