University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Monday, September 24th 2018
12:15 pm:
Speaker: Joshua A. Frieman, Fermilab
Subject: Probing Cosmology with the Dark Energy Survey

I will overview the Dark Energy Survey (DES) project and highlight its early science results, focusing on cosmology results from the first year of the survey. The DES collaboration built and is using the 570-megapixel Dark Energy Camera on the Blanco 4-meter telescope at NOAO's Cerro Tololo Inter-American Observatory in Chile to carry out a deep, wide-area, multi-band optical survey of several hundred million galaxies and a time-domain survey that has discovered several thousand supernovae. The survey started in Aug. 2013 and will finish early next year. DES was designed to address the questions: why is the expansion of the Universe speeding up? Is cosmic acceleration due to dark energy or does it require a modification of General Relativity? DES is addressing these questions by measuring the history of cosmic expansion and the growth of structure through multiple complementary techniques: galaxy clusters, the large-scale galaxy distribution, weak and strong gravitational lensing, and supernova distances, as well as through cross-correlation with other data sets, particularly the cosmic microwave background. I will also briefly discuss how the DES data are being used in unexpected ways, from probing dark matter with newly discovered ultra-faint dwarf galaxies to a new probe of the Hubble constant using the kilonova counterpart of a binary neutron star gravitational-wave source.

Faculty Host: Vuk Mandic

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