The Little Bangs created in ultra-relativistic heavy-ion collisions share many characteristic features with the cosmological evolution after the Big Bang. I will demonstrate how quantum fluctuations in the initial state of the Little Bang propagate via hydrodynamic evolution (supplemented by an early pre-equilibrated thermalization and a late kinetic freeze-out stage) into the experimentally observed final state, manifesting themselves as fluctuations in the final flow pattern. A harmonic analysis of the final flows, their transverse momentum dependence and their flow angles (the "Little Bang flow fluctuation spectrum") provides detailed experimental information from which theory allows to extract the spectrum of gluon fluctuations in the initial state, together with the transport coefficients of the quark-gluon plasma fluid created in the collisions.

Argonne Physics Division Colloquium Schedule