Fisher matrix for the one-loop galaxy power spectrum

• Verfasst von: Amendola, Luca [VerfasserIn]
• Verfasst von: Pietroni, Massimo [VerfasserIn]
• Verfasst von: Quartin, Miguel [VerfasserIn]
• Titel: Fisher matrix for the one-loop galaxy power spectrum
• Titelzusatz: measuring expansion and growth rates without assuming a cosmological model
• Verf.angabe: Luca Amendola, Massimo Pietroni and Miguel Quartin
• E-Jahr: 2022
• Jahr: 14 November 2022
• Umfang: 31 S.
• Fussnoten: Gesehen am 13.06.2023
• Titel Quelle: Enthalten in: Journal of cosmology and astroparticle physics
• Ort Quelle: London : IOP, 2003
• Jahr Quelle: 2022
• Band/Heft Quelle: (2022), 11 vom: Nov., Artikel-ID 023, Seite 1-31
• ISSN Quelle: 1475-7516
• DOI: doi:10.1088/1475-7516/2022/11/023
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1848870175

Abstract

We introduce a methodology to extend the Fisher matrix forecasts to mildly non-linear scales without the need of selecting a cosmological model. We make use of standard non-linear perturbation theory for biased tracers complemented by counterterms, and assume that the cosmological distances can be measured accurately with standard candles. Instead of choosing a specific model, we parametrize the linear power spectrum and the growth rate in several k and z bins. We show that one can then obtain model-independent constraints of the expansion rate E(z) = E(z)/H 0 and the growth rate f(k,z), besides the bias functions. We apply the technique to both Euclid and DESI public specifications in the range 0.6 ≤ z ≤ 1.8 and show that the gain in precision when going from k max = 0.1 to 0.2 h/Mpc is around two- to threefold, while it reaches four- to ninefold when extending to k max = 0.3 h/Mpc. In absolute terms, with k max = 0.2 h/Mpc, one can reach high precision on E(z) at each z-shell: 8-10% for DESI with Δz = 0.1, 5-6% for Euclid with Δz = 0.2-0.3. This improves to 1-2% if the growth rate f is taken to be k-independent. The growth rate itself has in general much weaker constraints, unless assumed to be k-independent, in which case the gain is similar to the one for E(z) and uncertainties around 5-15% can be reached at each z-bin. We also discuss how neglecting the non-linear corrections can have a large effect on the constraints even for k max = 0.1 h/Mpc, unless one has independent strong prior information on the non-linear parameters.