Supermobility and Zero Sound in DiluteHe3-He4Mixtures under Pressure

Experimental measurements of the osmotic pressure in liquid ${\mathrm{He}}^3$-${\mathrm{He}}^4$ mixtures made by Landau et al. suggest the possibility of a higher supermobile transition temperature than previously estimated, the possibility of $p$-state pair formation in the supermobile condensate, and the possibility of the existence of zero sound, for mixtures under sufficiently high external pressure.