Criticality of the loop O(2) model at the predicted transition point

Establish whether the loop $O(2)$ model is critical at $(n,x)=(2,1/\sqrt{2})$.

Background

The paper proves that translation-invariant Gibbs measures for the loop O(n)O(n) model have infinitely many loops surrounding every face throughout n[1,2]n\in[1,2] and x[1/2,1]x\in[1/\sqrt{2},1]. It specifically identifies the endpoint (2,1/2)(2,1/\sqrt{2}) as a conjecturally critical point, making its criticality an unresolved question distinct from the broader conjecture about the phase diagram.

References

The point~$n=2,x=1/\sqrt{2}$ is conjectured to be critical.

Planar percolation and the loop O(n) model  (2508.20917 - Glazman et al., 28 Aug 2025) in Section 1, Abstract