| ABSTRACT |
In this paper, we show that a pseudo-Nambu-Goldstone boson (PNGB) quintessence of spontaneous symmetry breaking (SSB) is responsible for an epoch of late-time cosmic acceleration. We suggest that an N = 2PNGB quintessence with SSB can give rise to the fast-roll cosmic acceleration in the evolution of the Universe. In the N = 2 PNGB quintessence model, the standard slow-roll condition in which the absolute value of the tachyonic mass squared vertical bar m(q)(2)vertical bar of this model is much less than the square of the Hubble constant H-2, is broken down to the fast-roll condition, vertical bar m(q)(2)vertical bar = O(H-2). However, the fast-rolling associated with the N = 2 PNGB quintessence of SSB is shown to lead to the epoch of late-time cosmic acceleration. Indeed, in our PNGB model, this epoch can be quite long-lasting because the mass of the N = 2 PNGB quintessence field is extremely small at m(q) approximate to 10(-33) eV. |
