Universal Sound Absorption in Amorphous Solids: A Theory of Elastically   Coupled Generic Blocks
  Glasses are known to exhibit quantitative universalities at low temperatures, the most striking of which is the ultrasonic attenuation coefficient 1/Q. In this work we develop a theory of coupled generic blocks with a certain randomness property to show that universality emerges essentially due to the interactions between elastic blocks, regardless of their microscopic nature. 
Dervis C. Vural and Anthony J. Leggett
cond-mat.dis-nn cond-mat.mtrl-sci cond-mat.stat-mech physics.atom-ph quant-ph