Closed universe and the first Doppler-peak of the CMB spectrum
  We study universe models which are intrinsically closed and are full of a quintessence scalar field, besides the Cold Dark Matter component. We use these to depict diverse flat Cold Dark Matter models. With the background geometry specified by the Friedman-Robertson-Walker metric, we include among them the standard Cold Dark Matter, the Cosmological Constant Cold Dark Matter and the Dark Energy or Quintessence Cold Dark Matter models. After describing these models, we determine the position of the first Doppler peak of the Cosmic Microwave Background anisotropy spectrum for $\Omega_T$ close to one; we also study the shift parameter $R$. 
Sergio del Campo