Experimental investigation of gravitationally induced effects in dynamical critical-point theories

The authors have experimentally examined the height dependence of the Rayleigh linewidth in C${\mathrm{O}}_2$ at $T-T_c=0.001\mathrm{}°$C. The results are compared with the predictions of the mode-mode coupling, decoupled mode, and dynamic-droplet theories of the critical point. Linewidth data are more easily described by the decoupled-mode theory than by other models.