Differentiating between modified gravity and dark energy

By A. Lue, R. Scoccimarro, Glenn Starkman. 2003

182 citations recorded by the source corpus.

The nature of the fuel that drives today's cosmic acceleration is an open and tantalizing mystery. We entertain the suggestion that the acceleration is not the manifestation of yet another new ingredient in the cosmic gas tank, but rather a signal of our first real lack of understanding of gravitational physics. By requiring that the underlying gravity theory respects Birkhoff's law, we derive the modified gravitational force-law necessary to generate any given cosmology, without reference to the fundamental theory, revealing modifications of gravity at scales typically much smaller than today's horizon. We discuss how through these modifications, the growth of density perturbations, the late-time integrated Sachs--Wolfe effect, and even solar-system measurements may be sensitive to whether today's cosmic acceleration is generated by dark energy or modified gravitational dynamics, and are subject to imminent observational discrimination. We argue how these conclusions can be more generic, and probably not dependent on the validity of Birkhoff's law.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/e50aa280b5ec67969e8fd4980be41d81550a2724

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In Astronomy and Astrophysics

Citations in the corpus

Cosmological constraints on f(R) gravity theories within the Palatini approach (2005, methodology): “Here we will follow a spherical collapse formalism (Lue et al. 2004a; Multamaki et al. 2003) where by requiring that a general gravity theory respects the Jebsen-Birkhoff theorem2 one derives the modified gravitational force law necessary to describe the evolution of the density perturbations at…”
Observational probes of cosmic acceleration (2012, background): “For example, modified gravity theories can mimic the effect of any particular equation of state evolution on the Hubble expansion rate and the distance-redshift relation while altering the rate of growth of large-scale structure (e.g., Lue et al. 2004; Song et al. 2007).”
f(R) Theories Of Gravity (2008, methodology): “Two different formalisms developed in (Hwang and Noh, 2002; Koivisto and Kurki-Suonio, 2006) and (Lue et al., 2004) were compared for the model f(R) = R − µ2(n+1)/Rn and it was found that the two models agree for scenarios that are “close” (in parameter space) to the standard concordance model, but…”
The phenomenology of Dvali–Gabadadze–Porrati cosmologies (2005, background): “Indeed, for a particular set of modified-gravity theories, this assertion is indeed the case [86].”