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arXiv · 1108.5385

Constructing Amplitudes from Their Soft Limits

Camille Boucher-Veronneau·Andrew J. Larkoski
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Abstract

The existence of universal soft limits for gauge-theory and gravity amplitudes has been known for a long time. The properties of the soft limits have been exploited in numerous ways; in particular for relating an n-point amplitude to an (n-1)-point amplitude by removing a soft particle. Recently, a procedure called inverse soft was developed by which "soft" particles can be systematically added to an amplitude to construct a higher-point amplitude for generic kinematics. We review this procedure and relate it to Britto-Cachazo-Feng-Witten recursion. We show that all tree-level amplitudes in gauge theory and gravity up through seven points can be constructed in this way, as well as certain classes of NMHV gauge-theory amplitudes with any number of external legs. This provides us with a systematic procedure for constructing amplitudes solely from their soft limits.

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Camille Boucher-Veronneau, Andrew J. Larkoski. 2011-10-14. Constructing Amplitudes from Their Soft Limits. https://doi.org/10.1007/jhep09(2011)130

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