Quantum gravity, gauge coupling constants, and the cosmological constant - High Energy Physics - TheoryReport as inadecuate




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Abstract: The quantization of Einstein-Maxwell theory with a cosmological constant isconsidered. We obtain all logarithmically divergent terms in the one-loopeffective action that involve only the background electromagnetic field. Thisincludes Lee-Wick type terms, as well as those responsible for therenormalization group behaviour of the electric charge or fine structureconstant. Of particular interest is the possible gauge condition dependence ofthe results, and we study this in some detail. We show that the traditionalbackground-field method, that is equivalent to a more traditional Feynmandiagram calculation, does result in gauge condition dependent results ingeneral. One resolution of this is to use the Vilkovisky-DeWitt effectiveaction method, and this is presented here. Quantum gravity is shown to lead toa contribution to the running charge not present when the cosmological constantvanishes. This re-opens the possibility, suggested by Robinson and Wilczek, ofaltering the scaling behaviour of gauge theories at high energies although ourresult differs. We show the possibility of an ultraviolet fixed point that islinked directly to the cosmological constant.



Author: David J. Toms

Source: https://arxiv.org/







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