2025/12/08 by Jiang, Jianping, Klausen, Frederik Ravn
#FOS: Mathematics #FOS: Physical sciences #Mathematical Physics (math-ph) #Probability (math.PR)
paper · doi:10.48550/arxiv.2512.07554
For the Ising model defined on aℤ2 at critical temperature with external field a15/8h, we give a simple and elementary proof that its truncated two-point function decays exponentially. The proof combines the high temperature expansion, random-cluster and random current representations. A new input in the proof is that, in the near-critical sourceless single current measure, there are many loops formed by a path on aℤ2 with diameter of order 1, together with two external edges that connect the path's endpoints to the ghost.