Gapless Topological Order, Gravity, and Black Holes

Understand

In this work we demonstrate that linearized gravity exhibits gapless topological order with an extensive ground state degeneracy.

• This phenomenon is closely related both to the topological order of the pyrochlore U(1) spin liquid and to recent work by Hawking et.
• al.
• who used the soft photon and graviton theorems to demonstrate that the vacuum in linearized gravity is not unique.