How to optimally parametrize deviations from general relativity in the evolution of cosmological perturbations

By Levon Pogosian, A. Silvestri, K. Koyama, Gong-Bo Zhao. 2010

142 citations recorded by the source corpus.

The next generation of weak lensing surveys will trace the growth of large scale perturbations through a sequence of epochs, offering an opportunity to test general relativity on cosmological scales. We review in detail the parametrization used in MGCAMB to describe the modified growth expected in alternative theories of gravity and generalized dark energy models. We highlight its advantages and examine several theoretical aspects. In particular, we show that the same set of equations can be consistently used on superhorizon and subhorizon linear scales. We also emphasize the sensitivity of data to scale-dependent features in the growth pattern, and propose using principal component analysis to converge on a practical set of parameters which is most likely to detect departures from general relativity. The connection with other parametrizations is also discussed.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/0b0016d4b4a2461dbc18af547505fc193c895a0e

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In Astronomy and Astrophysics

Citations in the corpus

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Measuring growth rate and geometry with anisotropic clustering (2013, methodology): “Next, we parametrize the linear equation of growth following the approach of Pogosian et al. (2010) as δ̈ + ( 2 + Ḣ ) δ̇ = 3 2 Ωm(z)Gδ (1 + µas) , (34) where δ is a matter overdensity, the overdot denotes a derivative with respect to ln a, G is the gravitational constant, and µ and s are…”
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Constraining modified gravity (2016, unknown): “At sub-horizon scales γ can be expressed in terms of GM following (32) of Pogosian et al. (2010) GM = 2 3 Ωγ−1m [ Ωγm + 2 + H ′ H + γ Ω′m Ωm + γ′ln(Ωm) ] (10) where primes indicate derivatives with respect to lna.”
Effective field theory of dark energy: A review (2019, methodology): “A systematic investigation of possible DE/MG extensions to GR can be performed using the μ,Σ, η phenomenological approach [150, 151, 152, 153] reviewed in Section 3.”
EMU: Evolutionary Map of the Universe (2011, background): “By modelling the EMU source distribution and bias, Raccanelli et al. (2011) have shown that significant limits can be placed on cosmological parameters (such as w and w 0 ) that describe dark energy, and on parameters Z and m that describe modifications to GR (Pogosian et al. 2010).”
Cosmology and Fundamental Physics with the Euclid Satellite (2012, methodology): “23), the conservation equations of matter perturbations can be expressed in the following form (see [737])”