# Are there quantum gravity theories in which spacetime itself is regarded as quantum in nature?

In quantum gravity, it's tried to quantize the gravitation. However, if I got it correctly, most quantum gravity approaches try only to quantize gravity as a force, the curvature of spacetime, not the spacetime itself. (Please correct if this is wrong.) The quantum effects of such theories are studied at the centres of gravity, where gravity is really strong.

In contrast, I would like to think about "how would it look like if the spacetime itself was the thing that we have to quantize to describe nature better?" In the general spherically symmetric solution to the Einstein Field Equations, the prefactor in front of the $$dr^2$$-component is always bigger than 1. And it is growing when mass increases. That can be written as 'with more mass, there is more space'. Therefore, for me, it seems plausible and reasonable that spacetime itself is something which adds up and needs to be quantized. The effects of such a theory could be studied at the far distance from the centres of gravity, where gravity is expected to be weak.

Are there theories which build up on that?

Or is there a reason not to look this way round?

Or do indeed the quantum gravity theories look this way round and I only got it wrong?

• There are plenty of them, take a look at Hossenfelder's article on them. Mar 31 at 7:53
• It's an interesting article. But looking for a minimal length scale is high energy gravity, densest possible packing of spacetime. "testing short distances requires focusing large energies in small volumes, and when energy densities increase, one finally cannot neglect anymore the curvature of the background." (in your link, introduction) - - - What I'm craving for instead is real background independence. Mar 31 at 8:39
• I deleted the edits which were done to my question. In detail, I deleted the word "discrete". The word "discrete" leads the question in direction to small scales, granular spacetime, high energies and high curvature, black-holes-related. However, my question is about spacetime itself without any other background, where there is low energy, no energy-related curvature, empty-space. Mar 31 at 9:01
• It seems likely that any theory of quantum gravity would regard spacetime as quantum in nature. Or do you mean something more specific with the phrase? Mar 31 at 9:01
• I have something in mind that is infinite in extension (radius) but finite in volume. Mar 31 at 9:09