Fig. 3: Universality of the coarsening speed D.
Our measurements for various interaction strengths show no systematic variation of D = dℓ2/dt (in the scaling regime) and give a combined estimate D = 3.4(3)ħ/m (solid line and shading). The four datasets shown in Figs. 1c or 2b are represented here by the corresponding coloured symbols. The purple triangle indicates a measurement for which we reduced the gas density n by a factor of 4.2, which reduces Tc ∝ n2/3 and the equilibrium condensed fraction (from about 60% to about 30%) but does not affect D. The green pentagon indicates a measurement for which we instead reduced the system volume V by a factor of 3.5; in this case, ℓ2 saturates at a correspondingly lower value (∝ V2/3) but again D is not affected. For details on the data taken with reduced n or V, see Extended Data Fig. 5. The data points corresponding to the same na values are slightly offset horizontally for visual clarity. The error bars reflect fitting errors.
