Quantum Cosmology from Group Field Theory Condensates: a Review

TL;DR

This review discusses deriving cosmological models from group field theory condensates, linking quantum gravity, Bose-Einstein condensates, and loop quantum cosmology to understand the universe's quantum origins.

Contribution

It provides a comprehensive overview of how to extract effective cosmological dynamics from GFT condensates and compares these with established quantum cosmology models.

Findings

Effective GFT condensate dynamics can be derived from microscopic quantum gravity.

Connections between GFT, LQG, and Bose-Einstein condensates are elucidated.

Comparison shows consistency with loop quantum cosmology predictions.

Abstract

We give, in some detail, a critical overview over recent work towards deriving a cosmological phenomenology from the fundamental quantum dynamics of group field theory (GFT), based on the picture of a macroscopic universe as a "condensate" of a large number of quanta of geometry which are given by excitations of the GFT field over a "no-space" vacuum. We emphasise conceptual foundations, relations to other research programmes in GFT and the wider context of loop quantum gravity (LQG), and connections to the quantum physics of real Bose-Einstein condensates. We show how to extract an effective dynamics for GFT condensates from the microscopic GFT physics, and how to compare it with predictions of more conventional quantum cosmology models, in particular loop quantum cosmology (LQC). No detailed familiarity with the GFT formalism is assumed.