Spontaneous Breaking of Lorentz-Invariance and Gravitons as Goldstone Particles

Abstract

We consider some aspects of spontaneous breaking of Lorentz Invariance in field theories, discussing the possibility that the certain tensor operators may condensate in the ground state in which case the tensor Goldstone particles would appear. We analyze their dynamics and discuss to which extent such a theory could imitate the gravity. We are also interested if the universality of coupling of such 'gravitons' with other particles can be achieved in the infrared limit. Then we address the more complicated models when such tensor Goldstones coexist with the usual geometrical gravitons. At the end we examine the properties of possible cosmological scenarios in the case of goldstone gravity coexisting with geometrical gravity.

Hamiltonian formulation of an effective modified gravity with nondynamical background fields

“…In the aftermath, further physicists took this idea over to gravity to interpret the graviton as a Goldstone boson linked to a spontaneous breakdown of local Lorentz and diffeomorphism invariance [51,52]. More recent works in the context of electrodynamics are [53,54] and for gravity we refer to [55][56][57][58] where the mechanism suggested in [55] is even considered as a solution of the cosmologicalconstant problem. In the context of gravity, it was demonstrated that an alternative gravity theory called cardinal gravity [57,58] can be constructed by means of a bootstrap method from a linearized theory with a two-tensor field that undergoes spontaneous Lorentz violation.…”

Emergent Models for Gravity: an Overview of Microscopic Models

“…This picture has been variously extended to the case of gravity [44,50,51,72,73,146,148,168,183]. For this more exotic case involving tensor fields, the background configuration is identified via conditions of the form…”

Spontaneous and Explicit Spacetime Symmetry Breaking in Einstein–Cartan Theory with Background Fields

“…Spontaneous breaking of spacetime symmetry has been widely investigated both theoretically and experimentally [17][18][19][20][21][22][23][24][25]102,103]. Specific mechanisms for how spontaneous breaking can occur have been identified and explored [14][15][16], and examples and properties of the NG modes that can arise have been studied [29,30,[104][105][106][107][108][109][110][111][112][113][114][115][116][117][118][119][120][121]. In the SME, both the pure-gravity and matter-gravity sectors have been constructed in EC theory [20].…”