Twistor Superstring in 2T-Physics
  By utilizing the gauge symmetries of Two-Time Physics (2T-physics), a superstring with linearly realized global SU(2,2|4) supersymmetry in 4+2 dimensions (plus internal degrees of freedom) is constructed. It is shown that the dynamics of the Witten-Berkovits twistor superstring in 3+1 dimensions emerges as one of the many one time (1T) holographic pictures of the 4+2 dimensional string obtained via gauge fixing of the 2T gauge symmetries. In 2T-physics the twistor language can be transformed to usual spacetime language and vice-versa, off shell, as different gauge fixings of the same 2T string theory. Further holographic string pictures in 3+1 dimensions that are dual theories can also be derived. The 2T superstring is further generalized in the SU(4)=SO(6) sector of SU(2,2|4) by the addition of six bosonic dimensions, for a total of 10+2 dimensions. Excitations of the extra bosons produce a SU(2,2|4) current algebra spectrum that matches the classification of the high spin currents of N=4, d=4 super Yang Mills theory which are conserved in the weak coupling limit. This spectrum is interpreted as the extension of the SU(2,2|4 classification of the Kaluza-Klein towers of typeII-B supergravity compactified on AdS{5}xS(5), into the full string theory, and is speculated to have a covariant 10+2 origin in F-theory or S-theory. Further generalizations of the superstring theory to 3+2, 5+2 and 6+2 dimensions, based on the supergroups OSp(8|4), F(4), OSp(8*|4) respectively, and other cases, are also discussed. The OSp(8|4) case in 6+2 dimensions can be gauge fixed to 5+1 dimensions to provide a formulation of the special superconformal theory in six dimensions either in terms of ordinary spacetime or in terms of twistors. 
Itzhak Bars