MG11 
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Abstract

Leading Log Solutions for SQED and Yukawa during Inflation

During inflation the quantum effects of massless, minimally coupled scalars and gravitons are vastly enhanced. In perturbative loop corrections this enhancement manifests as factors of the logarithm of the inflationary scale factor, which are known as ``Infrared logarithms.'' No matter how small the coupling constant, the continued expansion of spacetime must eventually increase the infrared logarithms to the point that perturbation theory breaks down. A reasonable approach for evolving past this breakdown is to resum the series of leading infrared logarithms. I apply Starobinskii's stochastic technique to accomplish this for scalar quantum electrodynamics and Yukawa theory (gr-qc/0602110).

Local versus Nonlocal Metric Modifications of Gravity

I review the classic result of Ostrogradskii which excludes all but a tiny subset of local, metric-based modifications of gravity. I then argue that the range of possible modifications becomes vastly larger and more interesting if one abandons locality. I also show how this can be done consistent with causality. This talk is based upon astro-ph/0601672.