We compute the scale dependence of fNL for models of multi-field inflation, allowing for an arbitrary field space metric. We show that, in addition to multi-field effects and self-interactions, the curved field space metric provides another source of scale dependence, which arises from the field-space Riemann curvature tensor and its derivatives. The scale dependence may be detectable within the near future if the amplitude of fNL is not too far from the current observational bounds.
|Number of pages
|Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
|Published - 8 Jan 2013
Bibliographical noteFunding Information:
We thank Joseph Elliston, Raquel Ribeiro, Misao Sasaki, David Seery and Reza Tavakol for useful discussions. J.G. thanks the Aspen Center for Physics for hospitality, supported in part by the National Science Foundation under Grant No. 1066293 , where part of this work was carried out. C.B. is supported by a Royal Society University Research Fellowship . J.G. is supported in part by a Korean–CERN Fellowship .