  We investigate the possibility that the matter of the universe has a
significant component (the quintessence component) determined by the equation
of state $p=w\rho$, with $w<0$. Here, we find conditions under which a closed
model may look like a flat Friedmann-Robertson-Walker universe at low redshift.
We study this problem in Einstein's general relativity and Brans-Dicke
theories. In both cases we obtain explicit expressions for the quintessence
scalar potential $V(Q)$, and the angular size as a function of the redshift.
