Authors: J J M Carrasco R Kallosh R Roiban A A Tseytlin
Publish Date: 2013/07/05
Volume: 2013, Issue: 7, Pages: 29-
Abstract
mathcalN = 4 Poincaré supergravity has a global SU1 1 duality symmetry that acts manifestly only on shell as it involves duality rotations of vector fields A U1 subgroup of this symmetry is known to be anomalous at the quantum level in the presence of a nontrivial gravitational background We first derive this anomaly from a novel perspective by relating it to a similar anomaly in conformal supergravity where SU1 1 acts off shell using the fact that mathcalN = 4 Poincaré supergravity has a superconformal formulation We explicitly construct the corresponding local and nonlocal anomalous terms in the oneloop effective action We then study how this anomaly is reflected in the supergravity Smatrix Calculating oneloop mathcalN = 4 supergravity scattering amplitudes with and without additional matter multiplets using color/kinematics duality and the doublecopy construction we find that a particular U1 symmetry which was present in the treelevel amplitudes is broken at the quantum level This breaking manifests itself in the appearance of new oneloop mathcalN = 4 supergravity amplitudes that have nonvanishing softscalar limits these amplitudes are absent in mathcalN 4 supergravities We discuss the relation between these symmetryviolating amplitudes and the corresponding U1 anomalous term in the oneloop supergravity effective action
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