Anomalous diffusion near the Fermi surface

We consider the three-dimensional dynamical evolution of localized hot spots in ultralow temperature Fermi liquids. Within a model calculation, it is found that such perturbations do not relax into a hydrodynamic profile at long times, as might be expected of thermal hot spots under less exotic conditions. Instead, the hot spot expands outward into a shell moving away from its center at a velocity comparable to the Fermi velocity υ_F, which is consistent with the "baked Alaska" hypothesis proposed earlier by Leggett as a possible solution to the riddle of B-phase nucleation in ³He.