Quantum graphity is a background independent condensed matter model foremergent locality, spatial geometry and matter in quantum gravity. The states of the system are given by bosonic degrees of freedom on a dynamical graph on N vertices (that is, changing in time). At high energy, the graph is the complete graph on N vertices and the physics is invariant under the full symmetric group acting on the vertices and highly non-local. We find evidence that the model has a phase, in which the ground state breaks the permutation symmetry to translations and rotations. In this phase the system is ordered, low-dimensional and local. The model gives rise to an emergent U(1) gauge theory in the ground state by the string-net condensation mechanism of Levin and Wen. After reviewing the model, we discuss how such an approach amounts to a new kind of quantum theory of gravity that has surprising large scale consequences and hence it is testable.
Room 348 at Theresienstr. 37
