  Dualities link M-theory, the 10+1 dimensional strong coupling limit of the
IIA string, to other 11-dimensional theories in signatures 9+2 and 6+5, and to
type II string theories in all 10-dimensional signatures. We study the
Freund-Rubin-type compactifications and brane-type solutions of these theories,
and find that branes with various world-volume signatures are possible. For
example, the 9+2 dimensional M* theory has membrane-type solutions with
world-volumes of signature (3,0) and (1,2), and a solitonic solution with
world-volume signature (5,1).

High Energy Physics - Theory