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arXiv · 1804.04980

Gauge Assisted Quadratic Gravity: A Framework for UV Complete Quantum Gravity

John F. Donoghue·Gabriel Menezes
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Abstract

We discuss a variation of quadratic gravity in which the gravitational interaction remains weakly coupled at all energies, but is assisted by a Yang-Mills gauge theory which becomes strong at the Planck scale. The Yang-Mills interaction is used to induce the usual Einstein-Hilbert term, which was taken to be small or absent in the original action. We study the spin-two propagator in detail, with a focus on the high mass resonance which is shifted off the real axis by the coupling to real decay channels. We calculate scattering in the $J=2$ partial wave and show explicitly that unitarity is satisfied. The theory will in general have a large cosmological constant and we study possible solutions to this, including a unimodular version of the theory. Overall, the theory satisfies our present tests for being a ultraviolet completion of quantum gravity.

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John F. Donoghue, Gabriel Menezes. 2018-04-13. Gauge Assisted Quadratic Gravity: A Framework for UV Complete Quantum Gravity. https://doi.org/10.1103/physrevd.97.126005

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