Self-avoiding-walk inequality for complete bunkbed graphs

Prove that the inequality between self-avoiding-walk counts, $|\mathscr{S}(u_0,v_0)|\leq|\mathscr{S}(u_0,v_1)|$, holds for the complete bunkbed graph $K_n\times K_2$ for every integer $n\geq3$.

Background

The paper studies self-avoiding walks on bunkbed graphs G×K2G\times K_2, comparing walks from u0u_0 to the same-layer vertex v0v_0 with walks from u0u_0 to the opposite-layer vertex v1v_1. For the complete base graph KnK_n, the authors prove equality when n=2n=2 and strict inequality in favor of the opposite-layer endpoint for n{3,4,5}n\in\{3,4,5\} and for all sufficiently large nn.

The conjecture asks whether this inequality holds uniformly for every remaining complete-graph size n3n\geq3, thereby extending the proven finite and asymptotic cases to all complete bunkbed graphs.

References

The inequality $\big|\mathscr{S}(u_0,v_0)\big|\leq \big| \mathscr{S}(u_0,v_1) \big|$ in \cref{thm: SAW on complete} holds for $K_n\times K_2$ for all $n\ge3$.

Maximum flow and self-avoiding walk on bunkbed graphs  (2502.06237 - Tang, 10 Feb 2025) in Conjecture following Theorem 3 (Section 1, Self-avoiding walk subsection)