Constraining the nature of dark energy

Constraining the nature of dark energy Constraining the nature of dark energy using the SKA
A. Torres-Rodríguez¹, C. Cress¹
¹ Astrophysics and Cosmology Research Unit, University of KwaZulu-Natal, Pietermaritzburg, 3209, South Africa.

The Integrated Sachs-Wolfe (ISW) effect arises when CMB photons streaming across the Universe interact with the time evolving gravitational potential wells associated with the foreground large scale structure. This interaction imprints a secondary anisotropy on the primordial CMB spectrum which can be used to probe the nature of dark energy driving the accelerated expansion of the Universe. A method for observing this effect is through cross-correlation of the CMB spectrum with a tracer of matter at low redshift. In this work, we study the detection of the ISW effect by the Square Kilometre Array (SKA) by presenting the theoretical predictions for the cross-power between the ISW fluctuations of the CMB and the expected projected field of HI galaxies up to redshift z ~ 2. Considering different models of the dark energy equation of state, we investigate the possibility for detection of its sound speed allowing, for example, a test of the quintessence hypothesis.

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On 20 Oct 2005, 17:41.