Constrains on the quintessence from observational data

摘要

We investigated a flat Universe where the quintessence has been approximated by the first order Chebyshev polynomials. We used different cosmologicalmeasurements: angular diameter, luminosity distance and the Hubble parameter to constrain it. The first two types of measurements favor a time dependent quintessence witha value of the quintessence at the present epoch higher than in the cosmological constant case. Hubble parameter measurements support a Universe close to the one givenby the cosmological constant case.