Graph explorer

Dark Energy Tomography

We study how parameter error forecasts for tomographic cosmic shear observations are affected by sky coverage, density of source galaxies, inclusion of CMB experiments, simultaneou fitting of non--dark energy parameters, and the parametrization of the history of the dark energy equation-of-state parameter w(z). We find tomographic shear-shear power spectra on large angular scales (l<1000) inferred from all-sky observations, in combination with Planck, can achieve sigma(w0)=0.06 and sigma(wa)=0.09 assuming the equation-of-state parameter is given by w(z)=w0+wa(1-a(z)) and that nine other matter content and primordial power spectrum parameters are simultaneously fit. Taking parameters other than w0, wa and Omegam to be completely fixed by the CMB we find errors on w0 and wa that are only 10% and 30% better respectively, justifying this common simplifying assumption. We also study `dark energy tomography&#39;: reconstuction of w(z) assumed to be constant within each of five independent redshift bins. With smaller-scale information included by use of the Jain & Taylor ratio statistic we find sigma(wi)<0.1 for all five redshift bins and sigma(wi)<0.02 for both bins at z<0.8. Finally, ad