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arXiv · 1512.01232

Double Soft Theorems and Shift Symmetry in Nonlinear Sigma Models

Ian Low
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Abstract

We show both the leading and subleading double soft theorems of the nonlinear sigma model follow from a shift symmetry enforcing Adler's zero condition in the presence of an unbroken global symmetry. They do not depend on the underlying coset G/H and are universal infrared behaviors of Nambu-Goldstone bosons. Although nonlinear sigma models contain an infinite number of interaction vertices, the double soft limit is determined entirely by a single four-point interaction, together with the existence of Adler's zeros.

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Ian Low. 2015-12-03. Double Soft Theorems and Shift Symmetry in Nonlinear Sigma Models. https://doi.org/10.1103/physrevd.93.045032

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