Bouncing cosmologies and accelerated expansion from quantum gravity condensates

by Marco De Cesare

Tuesday 13 Dec 2016, 14:30 → 15:30 Europe/Rome

2N44

I will discuss the cosmological implications of interactions between spacetime quanta in the Group Field Theory (GFT) approach to Quantum Gravity. The work I will present is part of a programme which aims at understanding Early Universe Cosmology by studying the dynamics of the emergent continuum spacetime, as obtained from a fundamentally discrete microscopic theory. In particular, we show how the initial singularity is replaced by a bounce, while GFT interactions lead to a recollapse of the Universe. It is remarkable that cyclic cosmologies are thus obtained in this framework without any a priori assumption on the geometry of spatial sections of the emergent spacetime. Furthermore, we show how interactions make it possible to have an early epoch of accelerated expansion, which can be made to last for an arbitrarily large number of e-folds, without the need to introduce an ad hoc potential for the scalar field. References: arXiv:1603.01764 , arXiv:1606.00352