Superstring Scattering Amplitudes with the Pure Spinor Formalism

Abstract

This thesis discusses how the pure spinor formalism can be used to efficiently compute superstring scattering amplitudes. We emphasize the pure spinor superspace form of the kinematic factors, where the simplifying features of this language have allowed an explicit relation among the massless four-point amplitudes at tree-level, one- and two-loops to be found. We show how these identities elegantly simplify the task of computing the amplitudes for all possible external state combination related by supersymmetry. In particular, the two-loop amplitudes involving fermionic states had never been computed before. By explicit calculation we show that the one- and two-loop amplitudes computed with the minimal and non-minimal formalisms are equivalent. Furthermore we compute the gauge variation of the massless six-point open string amplitude and obtain the kinematic factor related to the anomaly cancellation. We also discuss some preliminary results regarding the massless five-point amplitude at one-loop.

Ph.D Thesis from Sept. 2008, 108 pages, v2,v3: added references

References in corpus (8)

• ICTP Lectures on Covariant Quantization of the Superstring
• Y-formalism and $b$ ghost in the Non-minimal Pure Spinor Formalism of Superstrings
• Explaining the Pure Spinor Formalism for the Superstring
• Explaining Pure Spinor Superspace
• On the cohomology and inner products of the Berkovits superparticle and superstring
• Superstrings in General Backgrounds
• Note About Redefinition of BRST Operator for Pure Spinor String in General Background
• Superstring Sigma Model Computations Using the Pure Spinor Formalism

Cited by in corpus (2)

• Pure Spinor Vertex Operators in Siegel Gauge and Loop Amplitude Regularization
• Decoupling of unphysical states in the minimal pure spinor formalism II