Color fluctuations in hadrons and nucleus-nucleus collisions

Lorentz slowing down of interactions at high energies results in enhancement of effects due to color (transparency and opacity) fluctuations in colliding hadrons. This physics can be constructively incorporated into the dynamics of relativistic nuclear collisions through the concept of hadronic cross-section fluctuations. We summarize present knowledge of color fluctuations in hadrons extracted from studies of diffractive processes and inelastic shadowing, and calculation of these fluctuations in perturbative QCD. Color fluctuations lead to an enhancement of fluctuations in such observables as transverse energy and multiplicity, increase of nucleon-spectator yield in the central AA collisions, and trigger dependence of the nuclear parton distributions for central collisions. They also allow one to build effective triggers for enhanced quark delocalization in baryon-rich hadronic matter.