Titel:
Specific star formation rate, quenching and the evolution of ellipticals
across cosmic time

Abstract:
I will review recent results on the formation and evolution of
massive ellipticals inferred from both the stellar [X/Fe]-mass relation
in present-day galaxies as well as the chemical abundance pattern in
the ISM of their high redshift progenitors.
State-of-the-art chemical evolution models that reproduce such a large set of observables suggest a high redshift formation on short (< 1 Gyr) timescales (and high sSFR).
The steepness of the observed relations at z~0 is recovered by assuming that more massive galaxies form more efficiently than low mass ones.
The existence of such a positive slope also tells us that mergers must play a marginal role. In particular, a comparison of these results to
the predictions from semi-analytical models will highlight unsolved problems in the latter approach to galaxy evolution.

A non-negligible amount of dust is needed to explain the
observed abundance pattern at high redshift. The dust is due to
the production from supernovae and the most massive AGB stars as well
as from the grain growth in the interstellar medium.
We explore the possibility of QSO dust production.
These models can be applied to single well observed high-redshift
galaxies to infer their age and likely mass and morphology of
their descendants.

Finally, I will recast some of these findings in terms of the
recently derived cosmic evolution of the specific star formation rate.