1993/06/21 by Nathan Berkovits, Berkovits, Nathan
Physics and Astronomy · #Black Holes and Theoretical Physics #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-th
paper · pdf · doi:10.48550/arxiv.hep-th/9306109
(based on talks given at SUSY '93 and at Strings '93), 6 pages plain Tex, KCL-TH-93-9
arxiv created 1993/06/21 · openalex publication_date 1993/06/21 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
By replacing two of the bosonic scalar superfields of the N=2 string with fermionic scalar superfields (which shifts dcritical from (2,2) to (9,1)), a quadratic action for the ten-dimensional Green-Schwarz superstring is obtained. Using the usual N=2 super-Virasoro ghosts, one can construct a BRST operator, picture-changing operators, and covariant vertex operators for the Green-Schwarz superstring. Superstring scattering amplitudes with an arbitrary number of loops and external massless states are then calculated by evaluating correlation functions of these vertex operators on N=2 super-Riemann surfaces, and integrating over the N=2 super-moduli. These multiloop superstring amplitudes have been proven to be SO(9,1) super-Poincaré invariant (by constructing the super-Poincaré generators and writing the amplitudes in manifest SO(9,1) notation), unitary (by showing agreement with amplitudes obtained using the light-cone gauge Green-Schwarz formalism), and finite (by explicitly checking for divergences in the amplitudes when the Riemann surface degenerates). There is no multiloop ambiguity in these Green-Schwarz scattering amplitudes since spacetime-supersymmetry is manifest (there is no sum over spin structures), and therefore the moduli space can be compactified.