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Galaxy Power Spectrum in General Relativity

Nastassia Grimm
University of Zurich, Switzerland

In this talk, I present the impact of general relativistic effects on the galaxy power spectrum. After introducing the full general relativistic expression for the galaxy number density, I define the theory power spectrum and describe its relation to observations. Then, I discuss the issue of infrared divergence, as general relativistic effects have previously been believed to cause a divergent signal contaminating the measurement of primordial non-Gaussianity. I show that there is, in fact, no infrared divergence, as this unphysical behaviour vanishes when accounting for all general relativistic effects consistently. Finally, I present our numerical computation of the full galaxy power spectrum, showing the deviations from the standard prediction caused by the presence of non-divergent terms from relativistic corrections. I conclude that, as relativistic effects lead to significant corrections at low k, they need to be taken into account in the analysis of large-scale data.

2020 June 24, 16:00

Online broadcast (Zoom)

Instituto de Astrofísica e Ciências do Espaço Universidade do Porto Faculdade de Ciências da Universidade de Lisboa
Fundação para a Ciência e a Tecnologia COMPETE 2020 PORTUGAL 2020 União Europeia