The Integrated Sachs-Wolfe effect as a probe of non-standard cosmological evolution

Abstract

The Integrated Sachs-Wolfe effect is studied in non-standard cosmologies. By considering flat universes, it is shown how the quadrupole power can in principle be effectively suppressed by atypical evolution of the scale factor at a high redshift. However, an efficient suppression requires models that are very difficult to realize. The effect on the overall normalization of the CMB power spectrum is also discussed as non-standard cosmologies can affect the overall normalization significantly and enhance the primordial fluctuations. The possibility of constraining such non-standard models with CMB and independent measures of σ8, is discussed.