Université de GenèveDépartement de Physique ThéoriqueCAP Genève

A Consistency Relation for the Observed Galaxy Bispectrum and the Local non-Gaussianity from Relativistic Corrections

20. March 2015
Cite as: 
A. Kehagias, A. Moradinezhad-Dizgah, J. Noreña, H. Perrier, A. Riotto [arXiv: 1503.04467]

We obtain a consistency relation for the observed three-point correlator of galaxies. It includes relativistic effects and it is valid in the squeezed limit. Furthermore, the consistency relation is non-perturbative and can be used at arbitrarily small scales for the short modes. Our results are also useful to compute the non-linear relativistic corrections which induce a signal in the observations that might be misinterpreted as primordial non-Gaussianity with a local shape. We estimate the effective local non-Gaussianity parameter from the relativistic corrections. The exact value depends on the redshift and the magnification bias. At redshift of z=1, in the absence of magnification bias, we get a relativistic induced fNL of about 3.7.


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