ARGUMENTS FOR F-THEORY

Abstract

After a brief review of string and M-theory we point out some deficiencies. Partly to rectify them, we present several arguments for "F-theory", enlarging spacetime to (2, 10) signature, following the original suggestion of C. Vafa. We introduce a suggestive supersymmetric 27-plet of particles, associated to the exceptional symmetric hermitian space E6/ Spin c(10). Several possible future directions, including using projective rather than metric geometry, are mentioned. We should emphasize that F-theory is yet just a very provisional attempt, lacking clear dynamical principles.