CORRELATION LENGTHS IN ISING MODELS

J. M. Kim

V.P. Yurov, Al.B. Zamolodchikov

A program is proposed to study numerically the correlation functions in massive integrable 2D relativistic field theories. It relies crucially on the exact form factors of fields which can be reconstructed from the factorized scattering data. The correlation functions are expressible as infinite sums over intermediate asymptotic states. We suggest using computer power to perform the summation numerically. The convergence of the sum is tested for the simplest example of the scaling Ising spin-spin correlations (without magnetic field).

Th. Jolicœur, J. C. Le Guillou

The mass gap for the two-dimensional O (3) non-linear sigma model has been recently extracted from the Bethe Ansatz solution. Combining this result with the Renormalization Group treatment of the Quantum Heisenberg Ferromagnet as well as the Quantum non-linear sigma model we present new formulas for the correlation length of the square lattice quantum ferro and antiferromagnet.

M. Helm

H Ulman, M Athematics J Ournal

Leo P. Kadanoff