The Long Range Interaction and the Relaxation in Glasses at Low   Temperatures
  We describe the interaction stimulated relaxation in the ensemble of two-level systems, responsible for low temperature kinetics and thermodynamics properties of amorphous solids. This relaxation gets significant at sufficiently low temperature when phonons are substantially frozen out. We show that in the realistic experimental situation the measuring field strongly accelerates the interaction stimulated relaxation. The characteristic temperature and field dependences of the relaxation rate are found when the rate is affected both by the interaction between two level systems and by the external field. 
A. L. Burin, I. Ya. Polishchuk