The chemical evolution of the galactic bulge

In this paper we review the chemical evolution models for the Galactic bulg e: in particular, we discuss the predictions of models as compared with the available abundance data and infer the mechanism as well as the time scale for the formation of the Galactic bulge. We show that good chemical evolut ion models reproducing the observed metallicity distribution of stars in th e bulge predict that the [alpha/Fe] > 0 over most of the metallicity range. This is a very important constraint indicating that the bulge of our Galax y formed at the same time and even faster than the inner Galactic halo. We also discuss predictions for the evolution of light elements such as D and Li-7 and conclude that the D astration should be maximum due to the high st ar formation rate required for the bulge whereas the evolution of the abund ance of Li should be similar to that observed in the solar neighbourhood, b ut with an higher Li abundance in the interstellar medium at the present ti me.