6 Main theorem
Combining the primary estimate and the residual bound yields the main asymptotic expansion.
There exist \(C_0,c{\gt}0\) such that for all sufficiently large \(n\) and \(t\ge C_0 n^3\),
By the three-way decomposition, \(\mathbb {P}(S_{4t}=0) =K_n\operatorname {Re}\! \int _{\mathcal{D}_\mathrm {core}}\psi ^{4t}\, d\lambda +\operatorname {Re}E\), where \(E\) collects off-core and residual contributions. Proposition 22 gives the primary estimate. Proposition 25 gives \(|E|=O(e^{-cn^2})\hat A_{n,4t}\), absorbed by the existing \(O(e^{-cn^2})\) term. Since \(N_{n,4t}=2^{4nt}\mathbb {P}(S_{4t}=0)\) and \(A_{n,4t}=2^{4nt}\hat A_{n,4t}\), dividing by \(\hat A_{n,4t}\) yields the claim.
For every \(\varepsilon {\gt}0\) there exists \(K{\gt}0\) such that
For \(n\ge N_0\) (sufficiently large), the expansion in Theorem 26 bounds the ratio by \(\varepsilon \) when \(K\) is large enough. For each \(n{\lt}N_0\), the fixed-\(n\) asymptotics (Lemma 7) provide a threshold \(T_n\) beyond which the ratio is within \(\varepsilon \); enlarging \(K\) so that \(Kn^3\ge T_n\) for all small \(n\) completes the proof.