On novel string theories from 4d gauge theories

Abstract

We investigate strings theories as defined from four dimensional gauge theories. It is argued that novel (super)string theories exist up to 26 dimensions. Some of them may support weakly curved geometries.Comment: LateX, 17 pages. (v2) Removed showkeys command and added references (v3) Added new references and updated the discussion on space-time dependent couplings (v4) Added reference