Key points are not available for this paper at this time.
A new type of superstring theory is constructed as a chiral combination of the closed D=26 bosonic and D=10 fermionic strings. The theory is supersymmetric, Lorentz invariant, and free of tachyons. Consistency requires the gauge group to be Spin (32) {Z₂} or E₈E₈.
Gross et al. (1985) studied this question.