Neutrino spin-flavor oscillations in rapidly varying external fields
  We study neutrino spin-flavor oscillations in presence of rapidly varying external fields. The general formalism for the description of neutrino oscillations in arbitrary rapidly varying external fields is elaborated. We obtain the effective Hamiltonian which determines the evolution of the averaged neutrino wave function. We apply the general technique to neutrino oscillations in rapidly varying magnetic fields. The special case of the constant transversal and twisting magnetic fields is studied. We evaluate the effect of neutrino spin-flavor oscillations in rapidly varying magnetic fields of the Sun. The numerical solutions of the Schroedinger equation with the Hamiltonian accounting for the constant transversal and twisting magnetic fields are presented. We compare them with our approximate analytical transition probability formula and reveal good agreement at high frequencies of the twisting magnetic field. 
Maxim Dvornikov