2013/01/31 by Matteo Biagetti, Hideki Perrier, Antonio Riotto +1 · 1 citation
Physics and Astronomy · #astro-ph.CO #hep-ph
paper · pdf · doi:10.1103/physrevd.87.063521
11 pages, 7 figures
arxiv created 2013/03/25 · arxiv updated 2013/03/27
The primordial non-Gaussianity parameters fNL and tauNL may be scale-dependent. We investigate the capability of future measurements of the CMB mu-distortion, which is very sensitive to small scales, and of the large-scale halo bias to test the running of local non-Gaussianity. We show that, for an experiment such as PIXIE, a measurement of the mu-temperature correlation can pin down the spectral indices nfNL and ntauNL to values of the order of 0.3 if fNL = 20 and tauNL = 5000. A similar value can be achieved with an all-sky survey extending to redshift z ~ 1. In the particular case in which the two spectral indices are equal, as predicted in models where the cosmological perturbations are generated by a single-field other than the inflaton, then the 1-sigma error on the scale-dependence of the non-linearity parameters goes down to 0.2.