Detecting dark energy in orbit: The cosmological chameleon

By P. Brax, C. Bruck, A. Davis, J. Khoury, A. Weltman. 2004

424 citations recorded by the source corpus.

We show that the chameleon scalar field can drive the current phase of cosmic acceleration for a large class of scalar potentials that are also consistent with local tests of gravity. These provide explicit realizations of a quintessence model where the quintessence scalar field couples directly to baryons and dark matter with gravitational strength. We analyze the cosmological evolution of the chameleon field and show the existence of an attractor solution with the chameleon following the minimum of its effective potential. For a wide range of initial conditions, spanning many orders of magnitude in initial chameleon energy density, the attractor is reached before nucleosynthesis. Surprisingly, the range of allowed initial conditions leading to a successful cosmology is wider than in normal quintessence. We discuss applications to the cyclic model of the universe and show how the chameleon mechanism weakens some of the constraints on cyclic potentials.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/2b276032077950b4db50a87063f02709f9786486

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

Cosmology and Fundamental Physics with the Euclid Satellite (2012, background): “We mention here only that the presence of chameleon mechanisms [234, 887, 885, 235, 621, 236, 380] can, for example, modify the coupling depending on the environment.”
Galileon Cosmology (2009, background): “One is the chameleon mechanism [3, 4, 5]: by adding a suitable potential V (Φ), the scalar field acquires mass which depends on the density.”
Approaches to understanding cosmic acceleration (2009, background): “This general action encapsulates many models studied in the literature [110, 111, 99, 112, 113, 114, 115, 116].”
Cluster number counts dependence on dark energy inhomogeneities and coupling to dark matter (2005, background): “This is indeed a general feature of non-minimally coupled scalar fields, whose properties depend on the local density of the region they “live in” (Khoury & Weltman 2004; Mota & Barrow 2004a; Khoury & Weltman 2003; Clifton et al. 2004; Mota & Barrow 2004b; Brax et al. 2004)).”
Beyond the Cosmological Standard Model (2014, neutral): “This possibility was first explored in [184, 185, 273].”