Fundamental Physics and the Early Universe

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We live in the era of high precision cosmology. Over the next decade, a number of independent teams measuring the cosmic microwave background (CMB) and distribution of galaxies will give us a map of the matter in the universe of unprecedented size and detail. To date, such maps have been well explained by the inflationary paradigm, which postulates that the universe underwent a period of nearly exponential expansion during its earliest moments. In the process, inflation naturally seeded the formation of structures in our universe from quantum fluctuations that were stretched to cosmological scales by the expansion. This idea has been extraordinarily successful in explaining the observed cosmological data to date, but will face new challenges as we expand our view of the universe. The energy densities at these earliest moments were likely many orders of magnitude larger than have ever been observed directly. The predictions of inflation, and ultimately the formation of structure, are sensitive to the spectrum of particles and interactions at these incredible energies. In this sense, measurements of the CMB and large scale structures are a unique window into fundamental physics. However, existing data is not sufficient to determine the cause of inflation itself. Many drastically different mechanisms give rise to predictions compatible with current measurements. Furthermore, it is unclear how this situation will change in the future, as large scale structure surveys become our dominant source of cosmological information. This research will address these problems, both by identifying clear experimental targets that discriminate between inflationary mechanisms and by predicting the evolution of structure in our universe to sufficient accuracy to test inflation to the required precision. On the surface, the physics of inflation and large scale structure may seem are very different, but the theoretical techniques are very similar. In fact, recently both have seen great advances through the influx of ideas from particle physics. This research will further develop these tools and broaden their impact on the field of cosmology as a whole.