Breakthrough on dynamical higgs mechanism for dRGT gravity: Example in which graviton gains mass through electroweak phase transition

Abstract

Massive gravity is an interesting theoretical framework capable of explaining among others things cosmological IR (infra-red) phenomena like late-time cosmic acceleration. Unfortunately, it turned out to be very difficult of getting consistent massive gravity theory due, among other things, to ghost appearance and strong coupling break-down problems. Of course, even though since the work of de Rham, Gabadadge and Tolley; the ghost problem appears overcame; things remain unchanged for the strong coupling break-down problem which is the problem that a massive gravity of experimentally viable graviton mass $m$ has (in comparison of standard massless gravity theory) a very low cutoff-scale $\Lambda_3= \Big[m^2M_P\Big]^{\frac{1}{3}}$ above which the theory fails; a problem what must be resolved if we want massive gravity be a consistent physical theory which can pretend to describe nature. Now as we know, one of the better way of overcoming this strong coupling break-down problem of massive gravity is to have a dynamical Higgs mechanism for gravity capable of providing a clear-cut way of making the graviton massless dynamically above the cutoff-scale $\Lambda_3$; a challenge what turned out to be difficult to surmount. It is this difficult that I overcome in the present paper by showing that it is quite possible of getting a four-dimensional modified massless gravity theory which becomes dynamically massive through for example the dynamical standard model electroweak phase transition. More precisely, I propose the first example of dynamical Higgs mechanism for dRGT gravity permitting to overcome the strong coupling break-down problem of dRGT gravity.