SGER: Toward Model-Based Figures of Merit and Quantitative Goals for Dark Energy Experiments

University Of California-Davis, Davis CA

Investigators

Abstract

AST-0632901 Albrecht The discovery of the acceleration of the expansion of the Universe has galvanized physicists and astronomers, because it clearly requires new physics, either in exotic states of matter or as a modification of the fundamental theory of gravity. Although exciting and complementary experiments are already being proposed, the theoretical issues are so poorly understood that it is hard to set quantitative goals by which to judge the likely impact of different approaches. The National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the Department of Energy (DOE), together chartered a Dark Energy Task Force (DETF), through the federal advisory committee mechanism, to try to plan a sensible approach to determining the nature of dark energy. In order to make both quantitative and comparable assessments, the DETF has developed a metric, which is sure to cause considerable debate. It is essential to have such a figure-of-merit for evaluating experimental approaches to dark energy, but any specific choice is based on a selection of a theoretical framework (a parameterization). This project is an attempt to bring the issue of quantitative science goals for dark energy experiments to a new level. The results should be available soon after the DETF report is released, so that they can inform the discussion and acceptance of the report. The work will advance attempts to understand the dark energy, but will also allow students to contribute to this exhilarating topic, rated as "the most exciting science question of our time" by Science magazine. There is also a good chance to contribute significant assistance towards creating a more focused and effective experimental program. New metrics for dark energy experiments could transform the field, because of the current lack of any well-established, agreed-upon standards. This study will be carried out in an exploratory mode, with the faculty member working closely with a small group of students. The hope is that this will introduce the students to research that they might not be able to handle in a more traditional research setting. This work is funded from the Extragalactic Astronomy and Cosmology program of the Division of Astronomical Sciences, as a Small Grant for Exploratory Research. It is part of the interagency Physics of the Universe program.