I am a Professor of Astrophysics at the Dunlap Institute in the Department of Astronomy and Astrophysics at the University of Toronto in Canada.
Tel: +1 (416) 978-4971
Email: hlozek at dunlap dot
utoronto do ca
Using measurements from ACT and the Wilkinson Microwave Anisotropy Probe (WMAP), I placed constraints on the initial conditions of the universe. The primordial power spectrum of scalar fluctuations sets the initial conditions for all the structures we see today.
ACT is senstive to larger modes (smaller scales), and hence we can probe the primordial out to modes which are non-linear when using probes such as galaxies - in the CMB these modes are linear.
The left panel below (from Hlozek et al 2011.) illustrates the estimated power in bands using ACT+WMAP data with a prior on the Hubble constant today. The bottom right panel then translates these constraints on the primordial spectrum into constraints on the matter density today. ACT increases the window at larger scales, and provides complementary constraints to other cosmological probes.