Luttinger liquid parameter for the spin-1 Heisenberg chain in a magnetic   field
  A recently derived general formula and older numerical results are combined to deduce the behavior of the transverse correlation exponent for the spin-1 Heisenberg antiferromagnetic chain in an applied magnetic field: eta = 1/2 - (2.0)m +O(m^2), where m is the magnetization per site. A comparison with the O(3) non-linear sigma-model is also made. 
Ian Affleck