Threebranes in Twelve Dimensions
Recently we have seen great increases in the understanding of non-perturbative string theory in terms of the eleven dimensional M-theory structure [1, 2]. This understanding has been greatly enhanced by the realisation that many problems may be solved by the introduction of a signature (10,2) ‘F-theory’ [3]. To investigate this proposal further we discuss the formulation of a Green-Schwarz threebrane in twelve dimensions [4].