2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/192789Relativistic viscous hydrodynamic fits to RHIC data on the centrality dependence of multiplicity, transverse and elliptic flow for sqrt{s}=200 GeV Au+Au collisions are presented. For Glauber-type initial conditions, while data on integrated v_2 is consistent with a ratio of viscosity over entropy density up to eta/s=0.16, data on minimum bias v_2 seems to favor a much smaller viscosity over entropy ratio, below the bound from the AdS/CFT conjecture. Some caveats on this result are discussed.4 pages, 5 figures; v2: matches published version, title changed by journalNuclear TheoryHigh Energy Physics - PhenomenologyHigh Energy Physics - Theorytext