Quintessential inflation

Abstract

We present an explicit observationally acceptable model for evolution from inflation to the present epoch under the assumption that the entropy and matter of the familiar universe are from gravitational particle production at the end of inflation. This eliminates the problem of finding a satisfactory coupling of the inflaton and matter fields. Since the inflaton potential $V(φ)$ may be a monotonic function of the inflaton $φ$, the inflaton energy could produce an observationally significant effective cosmological constant, as in quintessence.

Figures (1)

• Figure 1: Evolution in quintessential inflation. The total mass density is plotted as a heavy solid line, the lighter line is the mass density in the inflaton, and the dashed line is the inflaton field value. The bottom curve is the density parameter (the fractional contribution to the square of the Hubble parameter by the mass densities in relativistic and nonrelativistic matter). The end of inflation, marked by the earliest (left-hand) filled squares, is defined by the maximum of $a(t)H(t)$ (the minimum value of the comoving Hubble length). Radiation-dominated expansion commences at the next squares. The next square indicates the epoch of equal mass densities in radiation and nonrelativistic matter. The last squares mark the present epoch at radiation temperature $T\sim 3^\circ$ K. The parameter $M$ in the potential (Eqs. \ref{['5']} to \ref{['6a']}) is chosen so the present value of the density parameter in matter is $\Omega _m=0.3$. The model for the matter assumes $R=1$ (Eq \ref{['14']}) and ${\cal N}_{\rm th} = 1000$ effective scalar fields at first thermalization. Annihilation of the extra fields at $T=1000$ GeV causes the step in the mass density at redshift $z\sim 10^{16}$ (Eq. \ref{['35']}).