# Quantum graphity: a model of emergent locality in quantum gravity

### APA

(2009). Quantum graphity: a model of emergent locality in quantum gravity. Perimeter Institute. https://pirsa.org/09030018

### MLA

Quantum graphity: a model of emergent locality in quantum gravity. Perimeter Institute, Mar. 11, 2009, https://pirsa.org/09030018

### BibTex

@misc{ pirsa_PIRSA:09030018, doi = {10.48660/09030018}, url = {https://pirsa.org/09030018}, author = {}, keywords = {Quantum Gravity}, language = {en}, title = {Quantum graphity: a model of emergent locality in quantum gravity}, publisher = {Perimeter Institute}, year = {2009}, month = {mar}, note = {PIRSA:09030018 see, \url{https://pirsa.org}} }

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Abstract

Quantum graphity is a background independent condensed matter model for emergent 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. 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. The ground state dynamically 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. In addition, in such a model, observable effects of emergent locality such as its imprint on the CMB can be studied. Finding the right dynamics for the desired ground state is ongoing work and I will review some of the basic results with an emphasis on the use of methods from quantum information theory such as topological order and the use of the Lieb-Robinson bounds to find the speed of light in the system.