Multipoles of the relativistic galaxy bispectrum
| Autor: | Chris Clarkson, Roy Maartens, Obinna Umeh, Eline M. De Weerd, Sheean Jolicoeur |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Line-of-sight Cosmology and Nongalactic Astrophysics (astro-ph.CO) 010308 nuclear & particles physics media_common.quotation_subject Spectral density RCUK FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Observer (physics) 01 natural sciences Universe Galaxy ST/P000592/1 Theoretical physics 0103 physical sciences astro-ph.CO ST/N000668/1 Invariant (mathematics) Relativistic quantum chemistry Bispectrum STFC media_common Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Weerd, E M D, Clarkson, C, Jolicoeur, S, Maartens, R & Umeh, O 2020, ' Multipoles of the relativistic galaxy bispectrum ', Journal of Cosmology and Astroparticle Physics, vol. 2020, no. 05, 018, pp. 1-36 . https://doi.org/10.1088/1475-7516/2020/05/018 |
| DOI: | 10.48550/arxiv.1912.11016 |
| Popis: | Above the equality scale the galaxy bispectrum will be a key probe for measuring primordial non-Gaussianity which can help differentiate between different inflationary models and other theories of the early universe. On these scales a variety of relativistic effects come into play once the galaxy number-count fluctuation is projected onto our past lightcone. By decomposing the Fourier-space bispectrum into invariant multipoles about the observer's line of sight we examine in detail how the relativistic effects contribute to these. We show how to perform this decomposition analytically, which is significantly faster for subsequent computations. While all multipoles receive a contribution from the relativistic part, odd multipoles arising from the imaginary part of the bispectrum have no Newtonian contribution, making the odd multipoles a smoking gun for a relativistic signature in the bispectrum for single tracers. The dipole and the octopole are significant on equality scales and above where the Newtonian approximation breaks down. This breakdown is further signified by the fact that the even multipoles receive a significant correction on very large scales. Comment: v3 has improved presentation. Version accepted by JCAP |
| Databáze: | OpenAIRE |
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