7 research outputs found
Constraining the Nature of Dark Energy using the SKA
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 CMB temperature
anisotropies are cross-correlated with galaxies detectable with the SKA in HI.
We consider using this measurement, the autocorrelation of HI 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 chi-square 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.Comment: 8 pages, 8 figures; updated references for publication MNRA