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“Understanding Cosmic Acceleration: Connecting Theory and Observation” Dr. Hiranya Peiris University of Chicago |
| Cosmic acceleration at early and late times are two of the biggest mysteries confronting cosmologists today. The initial conditions of the Big-Bang are thought to have been set during ``inflation'', an era of almost exponential expansion in the primordial universe. Inflation also provides a mechanism to generate the primordial fluctuations, anisotropies imprinted into the cosmic microwave background (CMB) radiation which result in the rich structure of matter today. Current cosmological data are, for the first time, precise enough to allow detailed observational tests of inflationary models. I will describe efforts to understand the microphysics of inflation, focusing in particular on CMB data. Intriguingly, several independent data sets show that the cosmological expansion may be once again accelerating. These observations lead to the conclusion that the universe is dominated by a negative-pressure component, ``dark energy'', which makes up roughly three-quarters of the cosmological energy density. Theoretical models for the dark energy include Einstein's cosmological constant, a dynamical component, etc. I will show how tools for extracting information about inflationary models can be used to constrain the physics of dark energy. |