  Large spatial density fluctuations in high-energy heavy-ion collisions can
come from many sources: initial transverse density fluctuations, non-central
collisions, phase transitions, surface tension, and fragmentations. The common
presence of some of these sources in high-energy heavy-ion collisions suggests
that large scale density fluctuations may often occur. The detection of large
density fluctuations by single-event Hanbury-Brown-Twiss interferometry in
heavy-ion collisions will provide useful information on density fluctuations
and the dynamics of heavy-ion collisions.
