Abstract
We have investigated the dynamic structure factor of room-temperature at two densities (0.25 and 0.63 times the critical) and at very low momentum transfer (0.3<κ<1.3 ). Linearized hydrodynamics agrees with the experimental data only at the higher density and κ<1 . However, the description in terms of three extended hydrodynamic modes is fully satisfactory at both densities over the whole κ range. We provide the first experimental evidence that the concept of extended hydrodynamic modes is valid for the whole range from hydrodynamics up into the kinetic regime.
- Received 6 August 1990
DOI:https://doi.org/10.1103/PhysRevLett.65.2394
©1990 American Physical Society