Observed Smooth Energy Fitted by Parametrized Quintessence

This paper proposes two phenomenological quintessence potentials with parameters fitted to the presently observed ratio $\rat$ of smooth energy to clustered mass and limits on the equation of state parameter $w_Q(a)=P/\rhoq$, for which the quintessence potential is now slow- or fast-rolling. These two potentials are intended to illustrate rather different quintessence phenomenology since tracking and into the near future. Neither can be a fundamental potential derivable from present-day string theory.