What predictions are made by asymptotically safe gravity?

Question

Various researchers are working on asymptotically safe gravity. If the idea is correct, what are the experimental consequences? How can the idea be tested in experiment?

Comments

The same as any other quantum theory of gravity, the direct predictions of the theory are at the Planck scales and for anything well below that we can be quite happy with tree-level quantum gravity. But you get these consistency criteria for asymptotic safety which constrain possible standard models, there is a pretty famous prediction of the Higgs boson mass. Taking this prediction at face value, the other, implicit prediction of that paper is that there are no other particles other than the Standard model. (But that would still leave neutrino mass and inflation unanswered, so I do not think this is to be taken too seriously.)

Answer 1

My impression is that the observed Higgs potential is not in fact compatible with asymptotic safety.

See the discussion at ncatlab.org/nlab/show/Higgs+field#AsymtoticSafetyOrNot summarizing p. 17-18 of

• Dario Buttazzo, Giuseppe Degrassi, Pier Paolo Giardino, Gian Giudice, Filippo Sala, Alberto Salvio, Alessandro Strumia, "Investigating the near-criticality of the Higgs boson", JHEP12(2013)089 (arXiv:1307.3536)

What is the case is that the observed Higgs potential stands out as being right on the line of meta-stability ncatlab.org/nlab/show/Higgs+field#MassAndVacuumInstability

This is compatible with asymptotic safety to first order. But it does not seem to be compatible to higher orders.