MNRAS-2010-Hikage-1505-11.pdf (695.9 kB)
Adiabatic versus isocurvature non-Gaussianity
journal contribution
posted on 2023-06-08, 14:49 authored by Chiaki Hikage, Dipak MunshiDipak Munshi, Alan Heavens, Peter ColesWe study the extent to which one can distinguish primordial non-Gaussianity (NG) arising from adiabatic and isocurvature perturbations. We make a joint analysis of different NG models based on various inflationary scenarios: local-type and equilateral-type NG from adiabatic perturbations and local-type and quadratic-type NG from isocurvature perturbations together with a foreground contamination by point sources. We separate the Fisher information of the bispectrum of cosmic microwave background temperature and polarization maps by l for the skew spectrum estimator introduced by Munshi and Heavens to study the scale dependence of the signal-to-noise ratio of different NG components and their correlations. We find that the adiabatic and the isocurvature modes are strongly correlated, though the phase difference of acoustic oscillations helps to distinguish them. The correlation between local- and equilateral-type is weak, but the two isocurvature modes are too strongly correlated to be discriminated. Point source contamination, to the extent to which it can be regarded as white noise, can be almost completely separated from the primordial components for l > 100. Including correlations among the different components, we find that the errors of the NG parameters increase by 20-30 per cent for the Wilkinson Microwave Anisotropy Probe 5-year observation, but ~=5 per cent for Planck observations.
History
Publication status
- Published
File Version
- Published version
Journal
Monthly Notices of the Royal Astronomical SocietyISSN
0035-8711Publisher
Wiley-BlackwellExternal DOI
Issue
3Volume
404Page range
1505-1511Department affiliated with
- Physics and Astronomy Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2013-04-29First Open Access (FOA) Date
2013-04-29First Compliant Deposit (FCD) Date
2013-04-29Usage metrics
Categories
No categories selectedLicence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC