Abstract
The primordial non-Gaussianity parameters and may be scale dependent. We investigate the capability of future measurements of the CMB 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 -temperature correlation can pin down the spectral indices and to values of the order of 0.3 if and . A similar value can be achieved with an all-sky survey extending to redshift . 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, the error on the scale dependence of the nonlinearity parameters goes down to 0.2.
- Received 15 January 2013
DOI:https://doi.org/10.1103/PhysRevD.87.063521
© 2013 American Physical Society