Hopfion canonical quantization
  We study the effect of the canonical quantization of the rotational mode of the charge Q=1 and Q=2 spinning Hopfions. The axially-symmetric solutions are constructed numerically, it is shown the quantum corrections to the mass of the configurations are relatively large. 
A. Acus, A. Halavanau, E. Norvaisas and Ya. Shnir
hep-th