Speaker
Description
I recall the old idea of 3rd quantization of gravity, generalizing the gravitational path integral to a sum over topologies, and proceed to illustrate how one could try to make mathematical sense of it, going discrete. I emphasize how this forces to adopt a different perspective, in line with emergent spacetime scenarios. I then introduce tensorial group field theories (TGFTs) for quantum gravity. They are a higher-dimensional generalization of random matrix models (and closely related to lattice quantum gravity and canonical loop quantum gravity), which gave the first concrete realization of the idea of 3rd quantization. Finally, I report on recent results showing the emergence of bouncing cosmologies with late-time cosmic acceleration, from the mean field approximation of quantum geometric TGFT models.
