Constraining the nature of dark energy using the Square Kilometer Array Telescope |
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| Authors: | A Torres-Rodríguez C M Cress |
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| Institution: | Astrophysics and Cosmology Research Unit, University of KwaZulu-Natal, Westville, 4000, South Africa |
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| Abstract: | We investigate the potential of the Square Kilometer Array Telescope (SKA) to constrain the sound speed of dark energy. The Integrated Sachs Wolfe (ISW) effect results in a significant power spectrum signal when Cosmic Microwave Background (CMB) temperature anisotropies are cross-correlated with galaxies detectable with the SKA in H i . We consider using this measurement, the autocorrelation of H i galaxies and the CMB temperature power spectrum to derive constraints on the sound speed. We study the contributions to the cross-correlation signal made by galaxies at different redshifts and use redshift tomography to improve the signal-to-noise. We use a χ2 analysis to estimate the significance of detecting a sound speed different from that expected in quintessence models, finding that there is potential to distinguish very low sound speeds from the quintessence value. |
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| Keywords: | cosmic microwave background cosmological parameters large-scale structure of the Universe radio lines: galaxies |
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