http://arxiv.org/abs/1908.11378
Primordial non-Gaussianity signatures of extremely heavy particles are re-examined within a simple alternative to the standard inflationary paradigm, in which the primordial fluctuations and the inflationary spacetime expansion are sourced by two different fields. The curvaton scenario provides an example of this in which the distinct roles are played by the curvaton and the inflaton fields, respectively. We study couplings of the curvaton to heavy particles with masses of order the inflationary Hubble scale, and show that they can lead to non-Gaussian signals orders of magnitude larger than those in standard inflation, consistent with explicit effective field theory control of inflationary dynamics. This brings various motivated particle physics signatures, such as loops of heavy gauge-charged scalars and fermions, within future observational reach. The curvaton paradigm can be viewed as a partial UV completion of effective field theories of only inflationary fluctuations in which large non-Gaussian signals of heavy particles have also been discussed, but in which inflationary dynamics is not explicitly derived.
S. Kumar and R. Sundrum
Mon, 2 Sep 19
4/66
Comments: 27 pages, 7 figures