RG Decimation — 1D Ising

Block-spin renormalization on the 1D Ising chain. Every other spin is integrated out (decimated), giving a new effective coupling K' = f(K).

RG recursion: K' = ½ ln(cosh 2K). Fixed points: K*=0 (high-T trivial), K*=∞ (low-T ordered, unstable in 1D). The 1D chain has no phase transition — only in 2D+.

Temperature T 1.00 Field h 0.00 N spins 32 Reset Step RG Auto RG