Cosmological implications of a scale invariant standard model

Abstract

Abstract:We generalize the standard model of particle physics such it displays global scale invariance. The gravitational action is also suitably modified such that it respects this symmetry. This model is interesting since the cosmological constant term is absent in the action. We find that the scale symmetry is broken by the recently introduced cosmological symmetry breaking mechanism. This simultaneously generates all the dimensionful parameters such as the Newton's gravitational constant, the particle masses and the vacuum or dark energy. We find that in its simplest version the model predicts the Higgs mass to be very small, which is ruled out experimentally. We further generalize the model such that it displays local scale invariance. In this case the Higgs particle disappears from the particle spectrum and instead we find a very massive vector boson.Hence the model gives a consistent description of particle physics phenomenology as well as fits the cosmological dark energy.

Local Scale Invariance and Inflation

“…Earlier, this model has been explored in the context to explain current acceleration of the universe [10][11][12]. This model does not have any dimensionful parameter.…”

“…There is no cosmological constant present in this theory because local scale symmetry is preserved here. However, the cosmological constant can be generated when the scale invariance is broken cosmologically [10]. Cosmological constant is constrained by the scale symmetry and hence it might solve the fine tuning problem associated with cosmological constant [12,13].…”

“…Cosmological constant is constrained by the scale symmetry and hence it might solve the fine tuning problem associated with cosmological constant [12,13]. Once the symmetry is broken, the other dimensionful parameter such as gravitational constant is also generated [10]. Thus, the scale invariance could be one of the appropriate symmetry to describe the current universe.…”

“…Some works related to removal of anomaly in conformal invariance and applications of conformal invariance have been discussed in Refs. [10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”

“…In addition, we assume S i = 0 since it does not play any role during the inflation. Considering a solution for S t , we break the scale invariance [10,11,24,25]. We call this phenomenon as "soft local scale symmetry breaking" [24,25] similar to spontaneous local symmetry breaking.…”