Cosmology Talk: Improved distance measurements with reconstructed WiggleZ

This is a talk I presented to cosmologists in the University of Oslo on May 20th 2014. For the layman interested in listening: I summarize recent results of analysis of cosmological large-scale measurements that we performed in the Australian WiggleZ Dark Energy Survey. In the analysis we analyze the manner in which galaxies are distributed on scales of hundreds of thousands of light-years, in order to measure geometrical aspects of the universe (rate of cosmic expansion, distances), with the goal to understand the evolution of the universe since the era of the cosmic microwave background. I end on a fun note displaying a non-astro project of mine called ``a-second-a-day". This is my video diary of 2013, in which every day I took a one second movie and compile to a short movie. Challenge for cosmologists -- count the number of Nobel prize winners are in the movie! Note: You might notice a hand flickering on the left side of the screen. This is because we had two sign language interpreters translating. For the advanced viewer (physicists, astronomers, cosmologists): I describe the results that are summarized in our paper http://arxiv.org/abs/1401.0358 where we show that we can improve distance measurements to a redshift of 1 by applying the reconstruction technique to the baryonic acoustic feature. Talk abstract: The baryonic acoustic oscillation imprint in galaxy maps has been shown to be a central tool in constraining cosmology. However, due to the growth of structure, which causes ~5Mpc shifts in galaxy positions, this 150 Mpc feature in the two-point correlation function becomes slightly blurred causing a degradation of its ability to constrain distances. In this talk I present the reconstruction technique which, by restoring information encoded in the matter density field, sharpens this standard ruler, and by so enhances its constraining power. We have recently applied this technique on the galaxy maps of the WiggleZ Dark Energy Survey (between z=0.2 and 1) , and find the method successful, significantly improving distance measurements. (see talk abstract here: http://www.mn.uio.no/astro/english/research/groups/cosmology/events/seminars/2014/kazin.html)