Spatial decay of temperature nonuniformities: The weakly interacting Bose gas

The spatial decay of temperature nonuniformities in the weakly interacting Bose gas is studied bv utilizing Ma's low-temperature solutions of the Boltzmann equation. These results, which give exponential decay lengths varying as T-9, may be relevant to He II for T0.1 K. The longest two decay lengths, 1 and 2, are found to be in nearly a ten-to-one ratio, with 13.41103 cm for He II at 0.1 K. At higher temperatures the decay lengths are expected to decrease less rapidly than T-9 because of phase-space considerations, but an extrapolation to 0.3 K does indicate 1 to be on the order of 1 cm. Two types of experiments are suggested for determining these lengths. It is pointed out that information about phonon dispersion can be obtained from such measurements. 1974 The American Physical Society.

Spatial decay of temperature nonuniformities: The weakly interacting Bose gas Academic Article