Probing primordial non-Gaussianity using large scale structure

Recent evidence from the WMAP satellite has lead to a tentative detection of non-Gaussianity. Using the bispectrum statistic applied to the MegaZ catalogue of over 600,000 luminous red galaxies we find new bounds on the large-scale nonGaussianity. We constrain the fNL parameter using a particular type of triangular configuration as well as the combination of all the possible triangles in harmonic space. The constraint on fNL from the combination of all possible triangular configurations is ffV'ial = 57 ± 52 with 68% confidence limit, which is consistent with vanishing primordial non-Gaussianity, although some triangular configurations on their own suggest a non-zero bispectrum which, if confirmed, would have a profound effect on modern cosmology.

Grantor dc:publisher.institution

Department of Astronomy

Year dc:date.issued

2009

Author dc:creator

• Fantaye, Yabebal

Advisors dc:contributor.advisor

• Bassett, Bruce
• Blake, Chris

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/6101

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/6101