4 ms·
Isn't 2+1 dimensions gravity a thing ? https://arxiv.org/abs/hep-th/9204099v3 https://arxiv.org/abs/hep-th/9204099v3
by balaise-rustine 3y ago
Isn't 2+1 dimensions gravity a thing ? https://arxiv.org/abs/hep-th/9204099v3 https://arxiv.org/abs/hep-th/9204099v3
- AlecBG 3y agoI think you end up with no degrees of freedom in 2+1 and below
- pa7x1 3y agoYes, and even 1+1 gravity theories, like JT-gravity (https://en.wikipedia.org/wiki/Jackiw%E2%80%93Teitelboim_gravity https://en.wikipedia.org/wiki/Jackiw%E2%80%93Teitelboim_grav...). But 2+1 Einstein's gravity is locally trivial (i.e. there are no local degrees of freedom) and is purely topological (i.e. holes and global structure of spacetime is what matters).