Constraints on dark energy and modified gravity from the ISW effect

I present a review of the combined measurement of the integrated Sachs-Wolfe (ISW) effect and its implication for cosmology, on its own and in combination with other data. I will first describe how this effect is created and how it can be detected with the cross-correlation of the cosmic microwave background (CMB) and some tracer of the large scale structure (LSS) of the Universe. I will describe our combined detection [T. Giannantonio et al., arXiv:0801.4380 [astro-ph].] obtained by measuring the two-point correlation functions between the WMAP CMB map and six different galaxy surveys. The significance of the detection is ∼4.5σ. The implications of such a measurement are that the concordance ΛCDM model is confirmed, and the magnitude of the detected ISW effect constrains at 95% confidence level. I describe in the following how these data can be combined with other data sets, such as type Ia supernovae, to obtain even stricter constraints on cosmology. Finally, I will mention the possible applications to distinguish between different gravity theories, such as the Dvali-Gabadaze-Porrati (DGP) model [T. Giannantonio, Y. S. Song & K. Koyama, arXiv:0803.2238 [astro-ph]] or f(R) theories.