Multibrane DGP model: Our universe as a stack of $(2+1)$-dim branes

Understand

We consider scenario in which our $(3+1)$-dim universe is actually a dense stack of multiple parallel $(2+1)$-dim branes.

• For this purpose, we generalize the DGP model to a multi-brane case.
• We solve for the propagation of the scalar field and gravity in this setup.
• At short distances (high momenta) along the branes interactions follow the $(2+1)$-dim laws, while at large distances (low momenta) interactions follow the usual $(3+1)$-dim laws.