# Continuum Relational Physics in Group Field Theories and Applications to Cosmology

### APA

Marchetti, L. (2023). Continuum Relational Physics in Group Field Theories and Applications to Cosmology. Perimeter Institute. https://pirsa.org/23120046

### MLA

Marchetti, Luca. Continuum Relational Physics in Group Field Theories and Applications to Cosmology. Perimeter Institute, Dec. 14, 2023, https://pirsa.org/23120046

### BibTex

@misc{ pirsa_PIRSA:23120046, doi = {10.48660/23120046}, url = {https://pirsa.org/23120046}, author = {Marchetti, Luca}, keywords = {Quantum Gravity}, language = {en}, title = {Continuum Relational Physics in Group Field Theories and Applications to Cosmology}, publisher = {Perimeter Institute}, year = {2023}, month = {dec}, note = {PIRSA:23120046 see, \url{https://pirsa.org}} }

Luca Marchetti University of New Brunswick

## Abstract

It is a general expectation in several approaches to quantum gravity that continuum physics emerges as a macroscopic phenomenon from the collective behavior of fundamental quantum gravity degrees of freedom. However, a physical understanding of this emergence process requires us to address deeply intertwined technical and conceptual issues. In this talk, I will focus on two of them: the localization problem, related to the background independence of the underlying quantum gravity theory, and the coarse-graining problem, related to the extraction of the macroscopic, continuum physics from the microscopic, quantum-gravitational one. After discussing what strategies can be adopted in general to address these issues, I will show a concrete implementation of such strategies in the context of the group field theory approach to quantum gravity. I will then demonstrate how these strategies can be employed to extract cosmological physics from group field theories, allowing to clarify the intrinsically quantum-gravitational nature of cosmic structures and to characterize the impact of quantum gravity effects on the emergent cosmological dynamics.

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Zoom link https://pitp.zoom.us/j/99070866809?pwd=Y1VGdGR5clZ0bTFwY2dBRHBwU3ptUT09