Dear all. I will be having an online seminar regarding my recently published paper https://iopscience.iop.org/article/10.1088/1402-4896/ad1d45 to a mainly specialist audience. I would be happy if you could ask me questions regarding the paper that are most likely to be asked by the audience who are specialist in General Relativity and Quantum Gravity. Your valuable feedback is highly appreciated.
What quantum gravity is, as a theory, isn't known, so the statement about energy and momentum in that context, seems problematic. First one must say what the theory is, then work out what energy and momentum in that framework could mean.
Anyone claiming to have a theory of quantum gravity must show how that theory resolves the spacetime singularities, that are the inevitable consequence of the fact that classical gravity is a gauge theory, whose group, that of diffeomorphisms, is noncompact.
A quantum theory of gravity isn't a theory of quantum matter in a classical spacetime, but a theory about the quantum fluctuations of the spacetime geometry itself.
In classical gravity energy and momentum is carried by matter and by gravitational waves. The latter describe the energy and momentum of the gravitational degrees of freedom. Both are perfectly well defined. So it's wrong to claim that (a) there are difficulties in defining energy and momentum in classical gravity and (b) that these can be resolved by quantum gravity.
There was some confusion about how to define the energy-momentum tensor of gravitational degrees of freedom, but that was before the mathematical description of gravitational waves was understood (and, eventually, before they were detected); now there's no excuse to continue being confused.
However it just doesn't make sense to talk of ``localization'' of energy and momentum, in any case.
Stuart Marongwe,
I will be grateful if you could provide us with the date of your online seminar and the names of the participants.
Thanks for considering my request.
Thank you for your participation and request. The provisos will be 22nd of February 2024. I will update you next week as well as provide a link to those who are interested in participating. I can confirm Prof Christian Corda will be there and some others who I cannot give out their names publicly without their permission.
Stam Nicolis
Thank you for your questions. If you read the article you will find that most of your questions are answered. I will clarify the aspects you raise in my talk. Thank you for your input.
Update Here's the teams link for those interested in participating on Thursday 22nd February 2024 . Starting 3pm CAT=GMT+2
https://teams.microsoft.com/l/meetup-join/19%3ameeting_YmVhMGRhYjItNTNlMC00ZjBjLWI2ZjktZTBkMDc1OTMzNTE2%40thread.v2/0?context=%7b%22Tid%22%3a%22222fdcbc-d8fd-45ec-a507-5999b5c5a72f%22%2c%22Oid%22%3a%229fa5b4b1-3cd2-4182-b2d0-6135a6438a67%22%7d