arXiv:0907.4238gr-qc
How Far Are We from the Quantum Theory of Gravity?
Early discovery. Linked by one identifiable commenter. This paper is outside the main ranking; a mention is not an endorsement.
Abstract
I give a pedagogical explanation of what it is about quantization that makes general relativity go from being a nearly perfect classical theory to a very problematic quantum one. I also explain why some quantization of gravity is unavoidable, why quantum field theories have divergences, why the divergences of quantum general relativity are worse than those of the other forces, what physicists think this means and what they might do with a consistent theory of quantum gravity if they had one. Finally, I discuss the quantum gravitational data that have recently become available from cosmology.
I keep this in one of my public social profiles. It has concrete math: https://arxiv.org/abs/0907.4238v1 "How Far Are We from the Quantum Theory of Gravity?"
lostmsuView on HNParent context