Constraining the Nature of Dark Energy using the SKA

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 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.

8 pages, 8 figures; updated references for publication MNRAS

References in corpus (3)

• Constraining dark energy with cross-correlated CMB and Large Scale Structure data
• Cross-correlation of WMAP 3rd year and the SDSS DR4 galaxy survey: new evidence for Dark Energy
• The Weak Clustering of Gas-Rich Galaxies

Cited by in corpus (7)

• The Effective Theory of Quintessence: the w<-1 Side Unveiled
• Theoretical Models of Dark Energy
• Dark energy with non-adiabatic sound speed: initial conditions and detectability
• The effect of reionization on the CMB-density correlation
• The CMBR ISW and HI 21-cm Cross-correlation Angular Power Spectrum
• Covariance of dark energy parameters and sound speed constraints from large HI surveys
• Accurate relativistic observables from post-processing light cone catalogues