Quantum gravity effects in black holes and cosmology

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For microscopic phenomena at the scale of the size of atoms or nuclei, it is well established that classical mechanics does not provide an accurate description of the physical world. At present the successful description of such small scale phenomena is provided by quantum mechanics, which is a strange and surprising theory, far removed from everyday intuitions about matter and motion. To arrive at a quantum description of nature, one begins with a classical description of the type developed by Newton and his successors, and applies to it a mathematical procedure called "quantization." This has worked well for three of the four known forces so far observed in nature. These are the electromagnetic, weak and strong nuclear forces. The quantization process produces a quantum theory, which can then be tested. It is an interesting fact that this procedure has worked work well for these three forces, but not for the forth one, which is the gravitational force. The reason why gravity is exceptional is due partly to the unusual classical description of it provided by Einstein as the dynamics of spacetime, and partly to the quantization procedure itself, which requires a fixed spacetime, also known as a "background." What appears to be required is a "background independent" quantization procedure. This proposal aims to apply such a quantization to two important problems that lie at the interface of quantum and classical gravity. The first is black hole physics and the second is cosmology. The goal of the first project is to probe the last stages of black hole radiation, and that of the second is to study how the assumptions of the standard model of cosmology might come from quantum gravity.