Emergent Dynamics of Spacetime and Matter from a Topological Phase

In this paper, we present a new theoretical scenario in which both dynamical Dirac fermions and Einstein's gravity with a positive cosmological constant and torsion emerge via a spontaneous symmetry breaking in a topological phase. This phase does not contain any local propagating degrees of freedom and is described by a metric-independent fermionic gauge theory, which is invariant under the de Sitter group. After breaking this group to its Lorentz subgroup through a dynamical Higgs mechanism, we show that fermions become dynamical and massive while the dynamics of the locally Lorentz-invariant spacetime can be induced via the condensation of the spinor field. Within our theory, both the Dirac mass and the Newton's constant of gravitation naturally emerge through well-known physical mechanisms.