A Solution to the electroweak horizon problem in the R_h=ct universe

Abstract

Particle physics suggests that the Universe may have undergone several phase transitions, including the well-known inflationary event associated with the separation of the strong and electroweak forces in grand unified theories. The accelerated cosmic expansion during this transition, at cosmic time t~10^{-36}-10^{-33} seconds, is often viewed as an explanation for the uniformity of the CMB temperature, T, which would otherwise have required inexplicable initial conditions. With the discovery of the Higgs particle, it is now quite likely that the Universe underwent another (electroweak) phase transition, at T=159.5 +/- 1.5 GeV---roughly ~10^{-11} seconds after the big bang. During this event, the fermions gained mass and the electric force separated from the weak force. There is currently no established explanation, however, for the apparent uniformity of the vacuum expectation value of the Higgs field which, like the uniformity in T, gives rise to its own horizon problem in standard LCDM cosmology. We show in this paper that a solution to the electroweak horizon problem may be found in the choice of cosmological model, and demonstrate that this issue does not exist in the alternative Friedmann-Robertson-Walker cosmology known as the R_h=ct universe.Comment: 6 pages, 2 figures. Accepted for publication in the European Physical Journal