SILVA NETO, G. P.; http://lattes.cnpq.br/6174707852888003; SILVA NETO, Gival Pordeus da.
Résumé:
The Hubble constant (H0) is considered a fundamental constant of cosmology. It is
crucial for any modern cosmological model, it is related to various cosmological quantities,
so it is extremely important a restrictive and accurate determination of its value. The
most recent estimate of H0 from local observations (z 1), H0 = 73:8 2; 4 kms�1Mpc�1,
and from high redshifts (z ' 1070), H0 = 67; 3 1; 2 kms�1Mpc�1, are discrepant in a
con dence level of 2; 4 . Within this context, Cunha and Lima (LC), in order to shed
some light on this problem, derived a new determination of H0 using four cosmological
tests at intermediate redshifts (z 1), based on the model called Flat CDM. They
obtained H0 = 74; 1 2; 2 kms�1Mpc�1, in full agreement with local measurements. In
this work, we explore the robustness of the result LC looking for systematic errors and
its dependence on the cosmological model used. We found that the H0 value from this
combined analysis is very weakly dependent on the underlying cosmological model, but the morphology adopted to infer the core radius of galaxy clusters, changes the estimates being the main source of systematic errors. Hence, we conclude that a better understanding of the morphology of the clusters is essential to transform this method in a powerful cross-check to H0.
