Using HII galaxies as a tracer of the high-z Hubble expansion

We will present cosmological results based on the use of an alternative to SNIa high-z cosmic expansion tracer. The correlation between the Hbeta emission-line luminosity and the stellar velocity dispersion provides a new distance indicator that extends to redshifts up to ~3-4. Using this new tracer we present results on the Hubble constant and on the Dark Energy equation of state parameters.