AGE CONSTRAINTS ON THE COSMIC EQUATION OF STATE

A large amount of recent observational evidence strongly suggests that we live in a flat, accelerating universe composed of ≃ 1/3 of matter (barionic + dark) and ≃ 2/3 of an exotic component with large negative pressure, usually called dark energy or "quintessence." In this contribution, we investigate observational constraints on the equation of state of the dark energy from age estimates of galaxy clusters, supernovae observations and CMB measurements. Our results are based on a flat Friedmann–Robertson–Walker (FRW) type models driven by non-relativistic matter plus a smooth dark energy component parametrized by a constant equation of state px = ωωx (ω < 0).