Star formation history in galaxies is strongly correlated to their present-day colors and the Hubble sequence can be considered as a sequence of different star formation history. Therefore we can model the cosmic star formation history based on the colors of local galaxies, and comparison to direct observations of luminosity density evolution at high redshift gives a new test for the cosmological parameters which is insensitive to merger history of galaxies. The luminosity density evolution in 0 < z < 1 observed by the Canada-France Redshift Survey in three wavebands of 2800Å, 4400Å, and 1μm indicates that the Λ-dominated flat universe with λ0 ∼ 0.8 (> 0.53 at 95%CL) is strongly favored.

The cosmic star formation rate (SFR) at z > 2 is also compared to the latest data of the Hubble Deep Field including new data which were not incorporated in the previous work of Totani, Yoshii, & Sato (1997), and our model of the luminosity density of spiral galaxies taking account of gas infall is consistent with the observations. Starbursts in elliptical galaxies, which are expected from the galactic wind model, however overproduce SFRs and hence they should be formed at z ≳ 5 or their UV emission has to be hidden by dust extinction. The amount of metals in galactic winds and escaping ionizing photons are enough to contaminate the Lyα forests or to reionize the universe.