Dynamical Properties of one dimensional Mott Insulators
  At low energies the charge sector of one dimensional Mott insulators can be described in terms of a quantum Sine-Gordon model. Using exact results derived from integrability it is possible to determine dynamical properties like the frequency dependent optical conductivity. We compare the exact results to perturbation theory and renormalisation group calculations. We also discuss the application of our results to experiments on quasi-1D organic conductors. 
Davide Controzzi, Fabian H.L. Essler and Alexei M. Tsvelik