Structure formation in the Dvali–Gabadadze–Porrati cosmological model

By K. Koyama, R. Maartens. 2005

135 citations recorded by the source corpus.

The DGP brane-world model provides an alternative to the standard LCDM cosmology, in which the late universe accelerates due to a modification of gravity rather than vacuum energy. The cosmological constant Λ in LCDM is replaced by a single parameter, the crossover scale rc, in DGP. The supernova redshift observations can be fitted by both models, with Λ ∼ H02 and rc ∼ H0−1. This degeneracy is broken by structure formation, which is suppressed in different ways in the two models. There is some confusion in the literature about how the standard linear growth factor is modified in the DGP model. While the luminosity distance can be computed purely from the modified four-dimensional Friedman equation, the evolution of density perturbations requires an analysis of the five-dimensional gravitational field. We show that if the five-dimensional effects are inappropriately neglected, then the four-dimensional Bianchi identities are violated and the computed growth factor is incorrect. By using the five-dimensional equations, we derive the correct growth factor.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/90315f87129c340667911fc69923ea3c5deb5498

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Brane-World Gravity (2004, methodology): “On subhorizon scales relevant for linear structure formation, 5D effects produce a difference between φ and −ψ [251]: k(2)φ = 4πGa(2) (︂ 1− 1 3β )︂ ρΔ , (427)”
f(R) Theories (2010, methodology): “On the sub-horizon scales larger than the Vainshtein radius, the equation for linear matter perturbations δm in the DGP model was derived in [400, 369] under a quasi-static approximation: δm + 2H?̇?m − 4πGeffρmδm ≃ 0 , (13.”
The Subaru FMOS galaxy redshift survey (FastSound). IV. New constraint on gravity theory from redshift space distortions at z ∼ 1.4 (2015, background): “On the scale of surveys we have that the effective Newton’s constant satisfies (Lue et al. 2004, Koyama & Maartens 2006): Geff = [ 1+ 1 3β(t) ] G0 , β(t)≡1−2Hrc ( 1+ Ḣ 3H2 ) .”