Boojums on the fermi surface in3He-A and Hamiltonian dynamics of the orbital momentum

Boojums (nodes) on the Fermi surface of³He-A lead to peculiar behavior of the intrinsic orbital momentum L in this superfluid. AtT=0, L has the form L=(ħ/2m₃)l(ρ-C₀), whereC₀≈ρ is the prefactor of the anomalous term in the supercurrent l(l rot l). From the algebra of the hydrodynamical Poisson brackets and from microscopic theory it follows thatC₀ is a dynamical invariant, (∂/∂t)C₀=0. The closed system of nonlinear hydrodynamic equations of³He-A atT=0 is constructed in the framework of the Poisson brackets scheme.