Gravitationalising the quantum: emergent gravity from spontaneous symmetry breaking
by
Giuseppe Meluccio
→
Europe/Rome
0M03
0M03
Description
The problem of recasting gravity as a gauge theory, akin to all quantum interactions, is a long-standing one. A formal unification of tetrads and spin connection into a single gauge field can be achieved by considering an extension of the Lorentz group. The Einstein–Cartan theory can then be shown to emerge as a consequence of the spontaneous symmetry breaking of a gauge symmetry in a pre-geometric 4D spacetime: starting from a specific formulation à la Yang–Mills of an SO(1,4) or SO(3,2) gauge theory without any spacetime metric, the Einstein–Hilbert action is recovered in the spontaneously broken phase after the identification of the effective spacetime metric and spin connection for the residual SO(1,3) gauge symmetry. The equivalence principle and background independence thereby emerge out of a more fundamental gauge principle, and the same can be said for the two mass parameters of General Relativity, i.e. the Planck mass and the cosmological constant. The phase transition from pre-geometry to a metric universe is caused by the dynamics of a Higgs-like field near the Planck scale, with implications for Cosmology. Furthermore, the algebra of constraints and the degrees of freedom of the theory are revealed by the Hamiltonian analysis. SUGGESTED LITERATURE: - A. Addazi, S. Capozziello, A. Marcianò, G. Meluccio, "Gravity from Pre-geometry", Class. Quantum Gravity 42, 045012 (2025) 10.1088/1361-6382/ada767 - F. Wilczek, "Riemann-Einstein Structure from Volume and Gauge Symmetry", Phys. Rev. Lett. 80, 4851–4 (1998) 10.1103/PhysRevLett.80.4851 - A. Randono, "Gauge Gravity: a forward-looking introduction", arXiv:1010.5822 (2010)
