The bispectrum of relativistic galaxy number counts
- Osservatorio Astronomico di Trieste, Università degli Studi di Trieste, Via Tiepolo 11, 34143 Trieste (Italy)
- Université de Genève, Département de Physique Théorique and CAP, 24 quai Ernest-Ansermet, CH-1211 Genève 4 (Switzerland)
We discuss the dominant terms of the relativistic galaxy number counts to second order in cosmological perturbation theory on sub-Hubble scales and on intermediate to large redshifts. In particular, we determine their contribution to the bispectrum. In addition to the terms already known from Newtonian second order perturbation theory, we find that there are a series of additional 'lensing-like' terms which contribute to the bispectrum. We derive analytical expressions for the full leading order bispectrum and we evaluate it numerically for different configurations, indicating how they can be measured with upcoming surveys. In particular, the new 'lensing-like' terms are not negligible for wide redshift bins and even dominate the bispectrum at well separated redshifts. This offers us the possibility to measure them in future surveys.
- OSTI ID:
- 22525078
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 01 Vol. 2016; ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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