Speaker
Description
The gravitational interaction, in the form of the Einstein–Cartan theory, can emerge from a pre-geometric gauge theory via a mechanism of spontaneous symmetry breaking. In this context, pre-geometry refers to the lack of a metric structure for spacetime, which can be recovered only in the spontaneously broken phase, below a critical energy near the Planck scale. The fundamental field of this formulation à la Yang–Mills is the gauge potential of the (anti-)de Sitter group, which yields both the tetrads and the spin connection of the Lorentz group after the spontaneous symmetry breaking. The Higgs-like field that allows such dynamics is a supermassive boson with implications for Cosmology. In the ultra-high-energy limit of the unbroken phase where the gauge symmetry is restored, the metric theory of gravity is then superseded by the pre-geometric one and all notions of spacetime singularity cease to be meaningful. At a cosmological level, a pre-geometric de Sitter universe is an exact and regular solution of the theory, and can represent the pre-geometric state of the early Universe from which the inflationary epoch emerges. This framework can thus provide a simple resolution for the problem of the Big Bang singularity.
