Low-damping slow modes of orientational nonlinear vibrations in liquid crystals in the presence of destabilizing magnetic fields

For nor linear inertial torsion vibrations of the structure of a nematic liquid crystal in a destabilizing magnetic field, there exist low-frequency modes with anomalously weak damping. The corresponding solution of a sine-Gordon-type equation, accounting for viscous rotational friction, describes the transitions between two equilibrium states separated by a potential barrier. We show that when the vibration amplitude is large enough to overcome the barrier, the ratio of the damping time to the vibration period diverges logarithmically. Translated from Teoreticheskaya i Matematicheskaya Fizika. Vol. 111, No. 1, pp. 132–143, April, 1997.