A test of the Suyama-Yamaguchi inequality from weak lensing

Grassi, Alessandra, Heisenberg, Lavinia, Byrnes, Christian T and Schäfer, Björn Malte (2014) A test of the Suyama-Yamaguchi inequality from weak lensing. Monthly Notices of the Royal Astronomical Society, 442 (2). pp. 1068-1078. ISSN 0035-8711

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Abstract

We investigate the weak lensing signature of primordial non-Gaussianities of the local type by constraining the magnitude of the weak convergence bi- and trispectra expected for the EUCLID weak lensing survey. Starting from expressions for the weak convergence spectra, bispectra and trispectra, whose relative magnitudes we investigate as a function of scale, we compute their respective signal to noise ratios by relating the polyspectra's amplitude to their Gaussian covariance using a Monte-Carlo technique for carrying out the configuration space integrations. In computing the Fisher-matrix on the non-Gaussianity parameters f_nl, g_nl and tau_nl with a very similar technique, we can derive Bayesian evidences for a violation of the Suyama-Yamaguchi relation tau_nl>=(6 f_nl/5)^2 as a function of the true f_nl and tau_nl-values and show that the relation can be probed down to levels of f_nl~10^2 and tau_nl~10^5. In a related study, we derive analytical expressions for the probability density that the SY-relation is exactly fulfilled, as required by models in which any one field generates the perturbations. We conclude with an outlook on the levels of non-Gaussianity that can be probed with tomographic lensing surveys.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QB Astronomy > QB0980 Cosmogony. Cosmology
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Depositing User: Christian Byrnes
Date Deposited: 27 May 2014 11:38
Last Modified: 07 Mar 2017 18:07
URI: http://sro.sussex.ac.uk/id/eprint/48815

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