Cosmology

As cosmologists we are interested in the origin, content and evolution of the Universe. For the first 360,000 years the Universe was in a very hot and dense state. Today we can measure the afterglow from the hot plasma in the early Universe, called the Cosmic Microwave Background (CMB). Observations of the CMB have transformed cosmology into a precision science. While the basic notion and the ingredients of an expanding universe are well established, fundamental questions remain. The polarization in the CMB provides a powerful tool to address the most important of these problems. Our group uses the polarization of the CMB as a probe of the early Universe and the matter content in the Universe, in particular the nature of dark matter. We develop and build specialized instrumentation to make ever more precise measurements of the CMB or to look for dark matter directly. We then transform the large data sets produced by these instruments into a better understanding of our Universe.