Cosmology from the Thermal Sunyaev-Zel'dovich Power Spectrum: Primordial
  non-Gaussianity and Massive Neutrinos
  We carry out a comprehensive analysis of the possible constraints on
cosmological and astrophysical parameters achievable with measurements of the
thermal Sunyaev-Zel'dovich (tSZ) power spectrum from upcoming full-sky CMB
observations, with a particular focus on one-parameter extensions to the LCDM
standard model involving local primordial non-Gaussianity (described by fNL)
and massive neutrinos (described by Mnu). We include all of the relevant
physical effects due to these additional parameters, including the change to
the halo mass function and the scale-dependent halo bias induced by local
primordial non-Gaussianity. [...] We compute forecasts for Planck, PIXIE, and a
cosmic variance (CV)-limited experiment, using multifrequency subtraction to
remove foregrounds and implementing two masking criteria based on the ROSAT and
eROSITA cluster catalogs to reduce the significant CV errors at low multipoles.
We find that Planck can detect the tSZ power spectrum with >30-sigma
significance, regardless of the masking scenario. However, neither Planck or
PIXIE is likely to provide competitive constraints on fNL from the tSZ power
spectrum due to CV noise at low-ell overwhelming the unique signature of the
scale-dependent bias. A future CV-limited experiment could provide a 3-sigma
detection of fNL~37, which is the WMAP9 maximum-likelihood result. The outlook
for neutrino masses is more optimistic: Planck can reach levels comparable to
the current upper bounds ~<0.3 eV with conservative assumptions about the
intracluster medium (ICM); stronger ICM priors could allow Planck to provide
1-2-sigma evidence for massive neutrinos from the tSZ power spectrum, depending
on the true value of the sum of the neutrino masses. We also forecast a ~<10%
constraint on the outer slope of the ICM pressure profile using the unmasked
Planck tSZ power spectrum.
