Don't Throw the Baby Out with the Bath Water
Abstract
I stress the importance of retaining a healthy classical limit while we search for an ultraviolet completion to quantum gravity. A key problem with negative-norm quantizations of higher derivative Lagrangians is that their classical limits do not correspond to real-valued metrics evolving in a real-valued spacetime. I also demonstrate that no completion based on the flat spacetime background S-matrix can suffice by providing an explicit example of a theory with unit S-matrix which still shows interesting changes in single-particle kinematics and in the evolution of its background. I discuss the implications of these considerations for the program of Asymptotic Safety. Finally, I urge that some attention be given to the possibility that quantum general relativity might make sense if only we could go beyond conventional perturbation theory.
Keywords
Cite
@article{arxiv.2306.09596,
title = {Don't Throw the Baby Out with the Bath Water},
author = {R. P. Woodard},
journal= {arXiv preprint arXiv:2306.09596},
year = {2023}
}
Comments
35 pages, 1 figure, uses LaTeX2e