Covariant Multiloop Superstring Amplitudes
نویسنده
چکیده
Talk given at Strings 2004 In these proceedings, the multiloop amplitude prescription using the super-Poincaré invariant pure spinor formalism for the superstring is reviewed. Unlike the RNS prescription , there is no sum over spin structures and surface terms coming from the boundary of moduli space can be ignored. Massless N-point multiloop amplitudes vanish for N < 4, which implies (with two mild assumptions) the perturbative finiteness of superstring theory. And R 4 terms receive no multiloop contributions in agreement with the Type IIB
منابع مشابه
Multiloop Amplitudes and Vanishing Theorems using the Pure Spinor Formalism for the Superstring Nathan Berkovits
A ten-dimensional super-Poincaré covariant formalism for the superstring was recently developed which involves a BRST operator constructed from superspace matter variables and a pure spinor ghost variable. A super-Poincaré covariant prescription was defined for computing tree amplitudes and was shown to coincide with the standard RNS prescription. In this paper, picture-changing operators are u...
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