In this talk, we construct Lorentz-invariant massive spin-2
theories in a flat space-time. Starting from the most general action of a massive spin-2 field whose Lagrangian contains up to quadratic in first derivatives of a field, we investigate new possibilities by using the Hamiltonian analysis. By imposing degeneracy of the kinetic matrix and the existence of subsequent constraints, we...
Probably not. I will introduce some different gravity theories which are as good as GR in the sense that all of constraints are first class and therefore a graviton has only 2 polarisations and the structure of the theory at low energies is thus expected to be stable against quantum corrections.
In arXiv:1811.09547 we introduced an interesting new Weyl-invariant and generally-covariant vector-tensor theory with higher derivatives. This theory can be induced by extending the mimetic construction to vector fields of conformal weight four. We demonstrated that in gauge-invariant variables this novel theory reduces to the Henneaux–Teitelboim description of the unimodular gravity. Hence,...
We investigate the spontaneous breaking of Weyl conformal geometry to Einstein gravity in the presence/absence of matter with non-minimal couplings and possible applications to model building beyond SM.
