It's now widely accepted...quantum corrections could be expected to take the form of noncommutative - Shahn Majid lecture
the simplest model of spacetime...they don't commute...there is evidence for this kind of model in 2 + 1 quantum gravity...what I'm going to show is, which is recent work in the last couple years...what we've shown is that, in fact, this very simple algebra has an intrinsic geometry. It's FORCED on you, just out of this algebra we will be led, and this philosophical position, we'll be led....so apart from this algebra, there is the question...you have to choose the differential structure...we know what "x" is but what is dx, the differential structure...we replace the manifold by algebra and we have to have something that encodes the differential structure in order to do physics...we have to encode the Leibniz rule...that encoding algebraically is the choice of the differential structure....
First you get a kind of vacuum energy...secondly the gravitational mass, ....this mg is no longer m... so the inertial and gravitational masses split off from the Klein-Gordon mass. So this suggests from very interesting behavior of quantum mechanics as you approach the Planck scale due to noncommutative geometry....
You discover something nice happens....the time dilation factor from where we are to the event horizon actually depends on energy. ... So time dilation becomes energy dependent, and once more, unlike the classical calculation where that factor blows up as you approach the horizon, in our case that factor is finite. So you don't have a sort of radiation...a sort of singularity in the red shift as you do classically....
Why we have a value that is so small compared to the Planck scale and yet not zero...it becomes non-zero due to quantum gravity corrections. That explains why it's so small....
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