# Simple example of renormalization

As far as I understand, the RG theory, or functional RG theory is a mathematical tool for moving in the "scale dimension". The tool can be used for calculation of Feigenbaums constant (e.g. mentioned here). Can the theory be given a simple example of how to move one "step" in the "scale dimension" ?

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Consider the spin-1/2 Ising model on a triangular lattice (see, e.g. Goldenfeld). – Steve Huntsman Apr 6 '11 at 13:22