Galaxy-CMB and Galaxy-Galaxy Lensing on Large Scales: Sensitivity to Primordial Non-Gaussianity

Loading...
Thumbnail Image
Penn collection
Department of Physics Papers
Degree type
Discipline
Subject
Physical Sciences and Mathematics
Physics
Funder
Grant number
License
Copyright date
Distributor
Related resources
Author
Jeong, Donghui
Komatsu, Eiichiro
Contributor
Abstract

A convincing detection of primordial non-Gaussianity in the local form of the bispectrum, whose amplitude is given by the ƒNL parameter, offers a powerful test of inflation. In this paper, we calculate the modification of two-point cross-correlation statistics of weak lensing—galaxy-galaxy lensing and galaxycosmic microwave background (CMB) crosscorrelation—due to ƒNL. We derive and calculate the covariance matrix of galaxy-galaxy lensing, including cosmic variance terms. We focus on large scales (l < 100) for which the shape noise of the shear measurement becomes irrelevant and cosmic variance dominates the error budget. For a modest degree of non-Gaussianity, ƒNL = ±50 modifications of the galaxy-galaxy-lensing signal at the 10% level are seen on scales R ~ 300 Mpc, and grow rapidly toward larger scales as ∝ R2. We also see a clear signature of the baryonic acoustic oscillation feature in the matter power spectrum at ~ 150 Mpc, which can be measured by next-generation lensing experiments. In addition, we can probe the local-form primordial non-Gaussianity in the galaxy-CMB lensing signal by correlating the lensing potential reconstructed from CMB with high-z galaxies. For example, for ƒNL = ±50, we find that the galaxy-CMB lensing cross-power spectrum is modified by ~ 10% at l ~ 40, and by a factor of 2 at l ~ 10, for a population of galaxies at z = 2 with a bias of 2. The effect is greater for more highly biased populations at larger z; thus, high-z galaxy surveys cross correlated with CMB offer a yet another probe of primordial non-Gaussianity.

Advisor
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Publication date
2009-12-22
Journal title
Volume number
Issue number
Publisher
Publisher DOI
Journal Issue
Comments
Suggested Citation: Jeong, D., E. Komatsu and B. Jain. (2009). "Galaxy-CMB and galaxy-galaxy lensing on large scales: Sensitivity to primordial non-Guassianity." Physical Review D. 80, 123527. © 2009 The American Physical Review. http://dx.doi.org/10.1103/PhysRevD.80.123527
Recommended citation
Collection