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ohwilleke

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- How would a quantum field theory of gravity massless spin-2 gravitons in Minkowski space differ generically or qualitatively from GR, if at all, and if there is a difference, how would it be experimentally measurable?

A central feature of classical GR that it is background independent and operates via a curvature in space-time. As I understand it, this is not true of the other Standard Model forces which are consistent with special relativity and operate in Minkowski space, in which forces are transmitted via carrier bosons, but is not consistent with GR.

As I understand it, in GR, locally space-time is approximately Minkowski space, but not exactly.

If gravity were formulated as a theory of a massless spin-2 boson that couple's to a particle's mass-energy in the same Minkowski space that Standard Model forces are modeled in with a coupling constants of the appropriate strength, how would that differ from classical GR? (I'm not saying that this is the right way or not the right way to do quantum gravity, just trying to understand what is at stake.)

I'm looking for differences that would be generically true or qualitatively different from all such theories, and not a particular non-existent working quantum gravity theory or calculations, which don't exist.

I'm asking about how any difference, if there is a difference, would be experimentally measurable as a way of stating and understanding more concretely the difference between the space-time topology in which the SM and special relativity alone operate, and the space-time topology of classical GR.

If that is too broad or speculative, in what circumstances would the differences (if any) probably be most obvious?

As I understand it, in GR, locally space-time is approximately Minkowski space, but not exactly.

If gravity were formulated as a theory of a massless spin-2 boson that couple's to a particle's mass-energy in the same Minkowski space that Standard Model forces are modeled in with a coupling constants of the appropriate strength, how would that differ from classical GR? (I'm not saying that this is the right way or not the right way to do quantum gravity, just trying to understand what is at stake.)

I'm looking for differences that would be generically true or qualitatively different from all such theories, and not a particular non-existent working quantum gravity theory or calculations, which don't exist.

I'm asking about how any difference, if there is a difference, would be experimentally measurable as a way of stating and understanding more concretely the difference between the space-time topology in which the SM and special relativity alone operate, and the space-time topology of classical GR.

If that is too broad or speculative, in what circumstances would the differences (if any) probably be most obvious?

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