Berkovits, N.2014-05-202014-05-202005-10-01Journal of High Energy Physics. Trieste: Int School Advanced Studies, n. 10, 29 p., 2005.1126-6708http://hdl.handle.net/11449/23554Following suggestions of Nekrasov and Siegel, a non-minimal set of fields are added to the pure spinor formalism for the superstring. Twisted (c) over cap = 3 N = 2 generators are then constructed where the pure spinor BRST operator is the fermionic spin-one generator, and the formalism is interpreted as a critical topological string. Three applications of this topological string theory include the super-Poincare covariant computation of multiloop superstring amplitudes without picture-changing operators, the construction of a cubic open superstring field theory without contact-term problems, and a new four-dimensional version of the pure spinor formalism which computes F-terms in the spacetime action.29engsuperstrings and heterotic stringstopological stringsArtigoWOS:000232976700089Acesso aberto