Universidad Complutense de Madrid
E-Prints Complutense

Parametrizing growth in dark energy and modified gravity models



Último año

Aparicio Resco, Miguel y López Maroto, Antonio (2018) Parametrizing growth in dark energy and modified gravity models. Physical review D, 97 (4). ISSN 2470-0010

Vista previa

URL Oficial: http://dx.doi.org/10.1103/PhysRevD.97.043518

URLTipo de URL


It is well known that an extremely accurate parametrization of the growth function of matter density perturbations in ACDM cosmology, with errors below 0.25%, is given by f(a) = Ω^(γ)_(m)(a) with γ ≃ 0.55. In this work, we show that a simple modification of this expression also provides a good description of growth in modified gravity theories. We consider the model-independent approach to modified gravity in terms of an effective Newton constant written as μ(a, k) = G_(eff)/G and show that f(a) = β(a) Ω^(γ)_(m)(a) provides fits to the numerical solutions with similar accuracy to that of ACDM. In the time-independent case with μ ¼ μðkÞ, simple analytic expressions for βðμÞ and γðμÞ are presented. In the time-dependent (but scaleindependent) case μ = μ(a), we show that β(a) has the same time dependence as μ(a). As an example, explicit formulas are provided in the Dvali-Gabadadze-Porrati (DGP) model. In the general case, for theories with μ(a, k), we obtain a perturbative expansion for β(μ) around the general relativity case μ = 1 which, for f(R) theories, reaches an accuracy below 1%. Finally, as an example we apply the obtained fitting functions in order to forecast the precision with which future galaxy surveys will be able to measure the μ parameter.

Tipo de documento:Artículo
Información Adicional:

© 2018 American Physical Society. We would like to thank M. Quartin for useful comments that motivated this work and Eric V. Linder for helpful comments. M. A. R. acknowledges support from a Universidad Complutense de Madrid predoctoral grant. This work has been supported by the Ministerio de Economía y Competitividad (Spain) projects No. FIS2014-52837-P, No. FIS2016-78859-P(AEI/ FEDER, UE), and Consolider-Ingenio MULTIDARK CSD2009-00064.

Palabras clave:Cosmological constant; Supernovae; Lambda; Space
Materias:Ciencias > Física > Física-Modelos matemáticos
Código ID:47208
Depositado:19 Abr 2018 11:33
Última Modificación:19 Abr 2018 11:53

Descargas en el último año

Sólo personal del repositorio: página de control del artículo