# Quantum gravity from quantum matter

### APA

Lee, S. (2022). Quantum gravity from quantum matter. Perimeter Institute. https://pirsa.org/22020047

### MLA

Lee, Sung-Sik. Quantum gravity from quantum matter. Perimeter Institute, Feb. 03, 2022, https://pirsa.org/22020047

### BibTex

@misc{ pirsa_PIRSA:22020047, doi = {10.48660/22020047}, url = {https://pirsa.org/22020047}, author = {Lee, Sung-Sik}, keywords = {Quantum Gravity}, language = {en}, title = {Quantum gravity from quantum matter}, publisher = {Perimeter Institute}, year = {2022}, month = {feb}, note = {PIRSA:22020047 see, \url{https://pirsa.org}} }

Sung-Sik Lee McMaster University

## Abstract

We present a model of quantum gravity in which dimension, topology and geometry of spacetime are collective dynamical variables that describe the pattern of entanglement of underlying quantum matter. As spacetimes with arbitrary dimensions can emerge, the gauge symmetry is generalized to a group that includes diffeomorphisms in general dimensions. The gauge symmetry obeys a first-class constraint operator algebra, and is reduced to a generalized hypersurface deformation algebra in states that exhibit classical spacetimes. In the semi-classical limit, we find a saddle-point solution that describes a series of (3+1)-dimensional de Sitter-like spacetimes with the Lorentzian signature bridged by Euclidean spaces in between.