Polyhedra, Moduli,
and Quantum Geometry

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On this page
  1. 15.1 The exact normalization and the result
  2. 15.2 A uniform double-sine estimate from its real integral
  3. 15.3 The smooth quantum phase and amplitude
  4. 15.4 The full contour and its tail estimate
  5. 15.5 Airy localization and the first correction
  6. 15.6 Numerical evidence and reproducibility status
  7. 15.7 Interpretation and scope

15 A uniform quantum Airy transition for the regular family

This section proves a statement for an explicitly specified meromorphic Barnes integral on the one-parameter regular slice. It does not assert a transition theorem for arbitrary six angle parameters, a three-manifold invariant, or an identification with the cone-metric measure. No novelty claim is made.

15.1 The exact normalization and the result

Take b>0b>0, Q=b+b−1Q=b+b^{-1}, and α=π−η2πb,ηE=arccos⁡(1/3),h=2πb2,λ=h1/3.\alpha=\frac{\pi-\eta}{2\pi b},\quad \eta_{\mathrm E}=\arccos(1/3),\quad h=2\pi b^2,\quad \lambda=h^{1/3}. For η\eta close to ηE\eta_{\mathrm E} and sufficiently small bb, choose an upward vertical contour CC satisfying Q<Re⁡w<4αQ<\operatorname{Re}w<4\alpha. This lies in the usual separating interval 3α<Re⁡w<min⁡(4α,2Q)3\alpha<\operatorname{Re}w<\min(4\alpha,2Q) and puts all three integrand arguments in their common fundamental strip. With the integrand of (14.25), namely Ib(w,η)=Sb(w−3α)4Sb(4α−w)3Sb(2Q−w),I_b(w,\eta)=S_b(w-3\alpha)^4 S_b(4\alpha-w)^3S_b(2Q-w), define ℛb(η)=Sb(3α−Q)2Sb(α)6∫CIb(w,η)⁡dwi.\mathcal R_b(\eta)= \frac{S_b(3\alpha-Q)^2}{S_b(\alpha)^6} \int_C I_b(w,\eta)\,\frac{\mathop{}\!\mathrm dw}{i}.(15.1) This is the equal-label symmetric formula (2.27) of [96, arXiv version 3], with the measure convention specified as ⁡dw/i\mathop{}\!\mathrm dw/i. If that formula’s printed ⁡dw\mathop{}\!\mathrm dw is read literally, its value is iℛbi\mathcal R_b. Keeping this constant phase explicit avoids imposing an unstated Barnes-measure convention. The four identical trivalent square roots multiply to the displayed quotient, with no remaining square-root choice. Absolute convergence and independence of the allowed vertical line are proved below.

The functional equation Sb(x+b−1)=2sin⁡(πx/b)Sb(x)S_b(x+b^{-1})=2\sin(\pi x/b)S_b(x) gives the exact identity Sb(3α−Q)2Sb(α)6=14sin⁡2((3η−π)/(2b2))Sb(3α−b)2Sb(α)6.\frac{S_b(3\alpha-Q)^2}{S_b(\alpha)^6} = \frac{1}{4\sin^2((3\eta-\pi)/(2b^2))} \frac{S_b(3\alpha-b)^2}{S_b(\alpha)^6}.(15.2) Accordingly define ℛ̂b(η)=4sin⁡2(3η−π2b2)ℛb(η)=Sb(3α−b)2Sb(α)6∫CIb(w,η)⁡dwi.\widehat{\mathcal R}_b(\eta) = 4\sin^2\!\left(\frac{3\eta-\pi}{2b^2}\right)\mathcal R_b(\eta) = \frac{S_b(3\alpha-b)^2}{S_b(\alpha)^6} \int_C I_b(w,\eta)\,\frac{\mathop{}\!\mathrm dw}{i}.(15.3) The right-hand side defines the continuation across the apparent singularities in the product on the left.

Proposition 15.1 (Uniform regular-family transition). For every fixed Z>0Z>0, put η=ηE−h2/362ζ,|ζ|≤Z.\eta=\eta_{\mathrm E} -\frac{h^{2/3}}{6\sqrt2}\,\zeta, \qquad |\zeta|\le Z. As b↓0b\downarrow0, the integral (15.3) satisfies, uniformly for these real ζ\zeta, ℛ̂b(η)=34h1/3b{Ai(ζ)−32h1/3Ai⁡′(ζ)+OZ(h2/3)}.\boxed{\quad \widehat{\mathcal R}_b(\eta)= \frac34\,\frac{h^{1/3}}{b} \left\{ \operatorname{Ai}(\zeta) -3\sqrt2\,h^{1/3}\operatorname{Ai}'(\zeta) +O_Z(h^{2/3}) \right\}. \quad}(15.4) The error inside braces is additive. The physical compact hyperbolic side has ζ≥0\zeta\ge0; negative ζ\zeta describes the analytic continuation across the Euclidean transition.

In particular the leading prefactor is 34(2π)1/3b−1/3\frac34(2\pi)^{1/3}b^{-1/3}. The correction can equivalently be written by replacing the Airy argument with ζ−32h1/3\zeta-3\sqrt2\,h^{1/3}, at an error OZ(h2/3)O_Z(h^{2/3}). The proof below controls the exact quantum integrand, the whole contour, its orientation, and the first correction.

15.2 A uniform double-sine estimate from its real integral

Let Λ\Lambda be the analytic primitive on 0<Re⁡z<π0<\operatorname{Re}z<\pi specified by Λ′(z)=−log⁡(2sin⁡z),Λ(π/2)=0,\Lambda'(z)=-\log(2\sin z),\qquad \Lambda(\pi/2)=0, with the logarithm real on (0,π)(0,\pi). On that real interval it is the usual Lobachevsky function.

Lemma 15.2 (Strip estimate). For zz in a compact subset of 0<Re⁡z<10<\operatorname{Re}z<1 and real κ\kappa in a bounded set, Sb(z/b+κb)=exp⁡(−Λ(πz)πb2)(2sin⁡πz)κ−1/2(1+O(b2)).S_b(z/b+\kappa b) = \exp\!\left(-\frac{\Lambda(\pi z)}{\pi b^2}\right) (2\sin\pi z)^{\kappa-1/2} \bigl(1+O(b^2)\bigr).(15.5) The logarithmic error and its derivatives are uniform on smaller compact subsets. For ε≤Re⁡z≤1−ε\varepsilon\le\operatorname{Re}z\le1-\varepsilon, the real part of the logarithmic error is Oε(b2)O_\varepsilon(b^2) uniformly for all Im⁡z\operatorname{Im}z.

Proof. We use Sb(x)=Γb(x)/Γb(Q−x)S_b(x)=\Gamma_b(x)/\Gamma_b(Q-x), with Γb(Q/2)=1\Gamma_b(Q/2)=1. The convergent real-integral normalization is log⁡Γb(x)=∫0∞⁡duu{e−xu−e−Qu/2(1−e−bu)(1−e−u/b)−(Q−2x)28e−u−Q−2x2u},Re⁡x>0.\log\Gamma_b(x)=\int_0^\infty\frac{\mathop{}\!\mathrm du}{u} \left\{ \frac{e^{-xu}-e^{-Qu/2}}{(1-e^{-bu})(1-e^{-u/b})} -\frac{(Q-2x)^2}{8}e^{-u}-\frac{Q-2x}{2u} \right\},\qquad \operatorname{Re}x>0. The first term in braces is (Q/2−x)/u+(Q/2−x)2/2+O(u)(Q/2-x)/u+(Q/2-x)^2/2+O(u) at zero, which fixes both subtractions. In [96, arXiv version 3, (A.1)] the last denominator is printed as uu; the factor 22 above is necessary for convergence. Subtracting the integrals at xx and Q−xQ-x therefore gives, for 0<Re⁡x<Q0<\operatorname{Re}x<Q, log⁡Sb(x)=∫0∞⁡duu{sinh⁡((Q/2−x)u)2sinh⁡(bu/2)sinh⁡(u/(2b))−Q−2xu}.\log S_b(x)=\int_0^\infty\frac{\mathop{}\!\mathrm du}{u} \left\{ \frac{\sinh((Q/2-x)u)} {2\sinh(bu/2)\sinh(u/(2b))} -\frac{Q-2x}{u} \right\}. This fixes a holomorphic logarithm, real on (0,Q)(0,Q) and zero at Q/2Q/2. At the centered argument x=z/b+b/2x=z/b+b/2, substitute u=2bsu=2bs and separate the term 1/(b2s)1/(b^2s) from csch⁡(b2s)\operatorname{csch}(b^2s). The result is log⁡Sb(z/b+b/2)=−Λ(πz)πb2+Db(z),\log S_b(z/b+b/2) =-\frac{\Lambda(\pi z)}{\pi b^2}+D_b(z),(15.6) where Db(z)=12∫0∞sinh⁡((1−2z)s)ssinh⁡s(csch(b2s)−1b2s)⁡ds.D_b(z)=\frac12\int_0^\infty \frac{\sinh((1-2z)s)}{s\sinh s} \left(\operatorname{csch}(b^2s)-\frac1{b^2s}\right)\mathop{}\!\mathrm ds.(15.7) Here the leading integral is the elementary identity 12∫0∞{sinh⁡((1−2z)s)sinh⁡s−(1−2z)}⁡dss2=−Λ(πz)π.\frac12\int_0^\infty \left\{\frac{\sinh((1-2z)s)}{\sinh s}-(1-2z)\right\} \frac{\mathop{}\!\mathrm ds}{s^2}=-\frac{\Lambda(\pi z)}{\pi}. For example, differentiating twice gives πcot⁡(πz)\pi\cot(\pi z) by the partial fraction expansion of the cotangent. Its first derivative at 1/21/2 is ∫0∞(s−2−(ssinh⁡s)−1)⁡ds=log⁡2\int_0^\infty(s^{-2}-(s\sinh s)^{-1})\mathop{}\!\mathrm ds=\log2, as follows from csch⁡s=coth⁡(s/2)−coth⁡s\operatorname{csch}s=\coth(s/2)-\coth s and a change of scale. Its value at 1/21/2 is zero. These three facts determine the primitive and its constant. For u>0u>0, |csch⁡u−u−1|≤Cu|\operatorname{csch}u-u^{-1}|\le C u. Near s=0s=0 the numerator sinh⁡((1−2z)s)\sinh((1-2z)s) is O(s)O(s), and at infinity the strip condition supplies exponential decay. This proves Db=O(b2)D_b=O(b^2) on compact subsets. Holomorphy and Cauchy’s estimate give the derivative statement.

For the global real-part bound use Re⁡sinh⁡((1−2z)s)=sinh⁡((1−2Re⁡z)s)cos⁡(2Im⁡zs).\operatorname{Re}\sinh((1-2z)s) =\sinh((1-2\operatorname{Re}z)s) \cos(2\operatorname{Im}z\,s). The same integrable bound is then independent of Im⁡z\operatorname{Im}z. Finally replace zz in (15.6) by z+(κ−12)b2z+(\kappa-\frac12)b^2 and Taylor expand the leading primitive. Its second and higher derivatives are bounded on closed substrips, including as |Im⁡z|→∞|\operatorname{Im}z|\to\infty. This gives (15.5) and the corresponding global modulus estimate. The centered variable is z=bx−b2/2z=bx-b^2/2. Its strip 0<Re⁡z<10<\operatorname{Re}z<1 is narrower than the fundamental xx-strip; no uniform small-bb estimate is asserted up to the boundary of that larger strip. ◻

15.3 The smooth quantum phase and amplitude

Use the corrected variable v=2πbwv=2\pi bw, and set θ1=12(v−3π+3η),θ2=12(4π−4η−v),θ3=12(4π−v),s=12(π−η).\begin{aligned} \theta_1&=\tfrac12(v-3\pi+3\eta),& \theta_2&=\tfrac12(4\pi-4\eta-v),\\ \theta_3&=\tfrac12(4\pi-v),& s&=\tfrac12(\pi-\eta). \end{aligned}(15.8) The three integrand arguments are θ1/(πb)\theta_1/(\pi b), θ2/(πb)\theta_2/(\pi b), and θ3/(πb)+2b\theta_3/(\pi b)+2b. The cleared prefactor uses 3s/(πb)−b3s/(\pi b)-b and s/(πb)s/(\pi b). All five scaled arguments are in a closed substrip near the fold. Lemma 15.2 therefore gives Sb(3α−b)2Sb(α)6Ib(w,η)=𝒜(v,η)eG(v,η)/h(1+O(h))\frac{S_b(3\alpha-b)^2}{S_b(\alpha)^6}I_b(w,\eta) = \mathcal A(v,\eta)\,e^{G(v,\eta)/h} \bigl(1+O(h)\bigr)(15.9) on compact subsets, where G(v,η)=−2{4Λ(θ1)+3Λ(θ2)+Λ(θ3)}+12Λ(s)−4Λ(3s),𝒜(v,η)=(2sin⁡θ1)−2(2sin⁡θ2)−3/2(2sin⁡θ3)3/2(sin⁡ssin⁡3s)3.(15.10)\begin{aligned} G(v,\eta) &=-2\{4\Lambda(\theta_1)+3\Lambda(\theta_2) +\Lambda(\theta_3)\} +12\Lambda(s)-4\Lambda(3s),\\ \mathcal A(v,\eta) &=(2\sin\theta_1)^{-2}(2\sin\theta_2)^{-3/2} (2\sin\theta_3)^{3/2} \left(\frac{\sin s}{\sin3s}\right)^3. \end{aligned} The powers are continued from their positive real values. For modulus estimates on the full vertical line, the same formula holds with a bounded multiplicative error, uniformly in its imaginary coordinate; this follows from the real-part estimate in the lemma.

At v*=4π−5ηEv_*=4\pi-5\eta_{\mathrm E} the exact values are θ1θ2θ3sin⁡θj1/31/31/(93)cot⁡θj222−112sin⁡ssin⁡3s=3.\begin{array}{c|ccc} &\theta_1&\theta_2&\theta_3\\ \hline \sin\theta_j&1/3&1/\sqrt3&1/(9\sqrt3)\\ \cot\theta_j&2\sqrt2&\sqrt2&-11\sqrt2 \end{array} \qquad \frac{\sin s}{\sin3s}=3. Consequently 𝒜*=94,(log⁡𝒜)v|*=72.\mathcal A_*=\frac94,\qquad (\log\mathcal A)_v\big|_*=7\sqrt2.(15.11) The phase has the following fold data; its value is justified below, and its derivatives follow from (15.10): G*=Gv|*=Gvv|*=Gη|*=0,Gvvv|*=54,Gvη|*=182,Gηη|*=362,Gvvvv|*=−6482,Gvvη|*=−18.\begin{gathered} G_*=G_v|_*=G_{vv}|_*=G_\eta|_*=0,\\ G_{vvv}|_*=54,\qquad G_{v\eta}|_*=18\sqrt2,\qquad G_{\eta\eta}|_*=36\sqrt2,\\ G_{vvvv}|_*=-648\sqrt2,\qquad G_{vv\eta}|_*=-18. \end{gathered}(15.12) The value G*=0G_*=0 requires fixing the constant, not just differentiating the phase. Use the real Lobachevsky form of [83, Section 1.2, (1.14)–(1.18)], extending the real function by oddness and period π\pi. For equal angles its potential and correction are UΛ(v,η)=Λ(v/2)+3Λ(v/2+2η−π)−4Λ((v+3η−π)/2),ΔΛ(η)=2Λ((3η−π)/2)−6Λ((η−π)/2).\begin{split} U_\Lambda(v,\eta) &=\Lambda(v/2)+3\Lambda(v/2+2\eta-\pi) -4\Lambda((v+3\eta-\pi)/2),\\ \Delta_\Lambda(\eta) &=2\Lambda((3\eta-\pi)/2)-6\Lambda((\eta-\pi)/2). \end{split} Periodicity and oddness give, term by term, UΛ=−4Λ(θ1)−3Λ(θ2)−Λ(θ3),ΔΛ=6Λ(s)−2Λ(3s),G=2(UΛ+ΔΛ).\begin{split} U_\Lambda&=-4\Lambda(\theta_1)-3\Lambda(\theta_2) -\Lambda(\theta_3),\\ \Delta_\Lambda&=6\Lambda(s)-2\Lambda(3s),\qquad G=2(U_\Lambda+\Delta_\Lambda). \end{split} At the two unit-circle saddle roots on the compact hyperbolic side, Theorem 2 of that paper, in this real formulation, says |UΛ+ΔΛ|=W|U_\Lambda+\Delta_\Lambda|=W. Both roots converge to the lift v*v_*, while the regular tetrahedral volume tends to zero by (14.20). Continuity proves G*=0G_*=0. This argument fixes the real constant without selecting unspecified branches of a complex dilogarithm.

15.4 The full contour and its tail estimate

The poles of the first double-sine factor are at w=3α−mb−n/bw=3\alpha-mb-n/b; the other two factors have their poles at w=4α+mb+n/bw=4\alpha+mb+n/b and w=2Q+mb+n/bw=2Q+mb+n/b. Thus the separating interval remains nonempty for 0<α<2Q/30<\alpha<2Q/3. Decreasing the equal real labels from α=Q/2\alpha=Q/2 to the compact values preserves this interval. Along this path α>Q/4\alpha>Q/4, so one may choose max⁡(3α,Q)<Re⁡w<4α≤2Q\max(3\alpha,Q)<\operatorname{Re}w<4\alpha\le2Q and keep all three arguments in the common strip throughout. The integral has no pinch on this path.

First justify moving an arbitrary defining contour to the fold neighborhood at each fixed bb. The vertical asymptotics [96, (A.11) and (A.13)] give |Sb(a+iT)|=eπ(a−Q/2)|T|(1+o(1)),|T|→∞,|S_b(a+iT)|=e^{\pi(a-Q/2)|T|}(1+o(1)),\qquad |T|\to\infty, uniformly for aa in a fixed compact real interval. The sum of the coefficients in the eight factors of IbI_b is 4(wR−3α−Q/2)+3(4α−wR−Q/2)+(2Q−wR−Q/2)=−2Q.4(w_R-3\alpha-Q/2)+3(4\alpha-w_R-Q/2) +(2Q-w_R-Q/2)=-2Q. Consequently |Ib(wR+iT,η)|=O(e−2πQ|T|)|I_b(w_R+iT,\eta)|=O(e^{-2\pi Q|T|}), uniformly between any two fixed separating lines. Horizontal closing segments vanish and no poles are crossed. This proves absolute convergence, contour independence, and agreement with the continued contour in (2.27). The same bound is locally uniform for complex α\alpha near the real continuation path, so the integral is holomorphic there. The external factor is meromorphic; (15.2) removes its poles on this path. In a neighborhood of the fold, both remaining prefactor arguments are in (0,Q)(0,Q), and the cleared expression is holomorphic and real for real η\eta.

Only after this fixed-bb relocation do we apply the uniform centered-strip estimates near v*v_*. They apply to the entire vertical line there, including its unbounded imaginary part.

On the vertical line v=v*+iyv=v_*+iy at η=ηE\eta=\eta_{\mathrm E}, put r=tanh⁡(y/2)r=\tanh(y/2). For y>0y>0, direct differentiation gives −⁡d⁡dyRe⁡G(v*+iy,ηE)=Ψ(r),-\frac{\mathop{}\!\mathrm d}{\mathop{}\!\mathrm dy}\operatorname{Re}G(v_*+iy,\eta_{\mathrm E}) =\Psi(r),(15.13) where Ψ(r)=4arctan⁡(22r)+3arctan⁡(2r)−arctan⁡(112r).\Psi(r)=4\arctan(2\sqrt2r) +3\arctan(\sqrt2r)-\arctan(11\sqrt2r). Here Ψ(0)=0\Psi(0)=0 and Ψ′(r)=8642r2(3+11r2)(1+8r2)(1+2r2)(1+242r2)>0(r>0).\Psi'(r)= \frac{864\sqrt2\,r^2(3+11r^2)} {(1+8r^2)(1+2r^2)(1+242r^2)}>0 \qquad(r>0).(15.14) It follows that the fold is the unique maximum of the real part of GG on this vertical line. In addition, Re⁡G(v*+iy,ηE)=−272y4+O(y6),Ψ(tanh⁡(y/2))→2π(y→+∞).\operatorname{Re}G(v_*+iy,\eta_{\mathrm E}) =-27\sqrt2\,y^4+O(y^6),\qquad \Psi(\tanh(y/2))\longrightarrow2\pi \quad(y\to+\infty). Complex conjugation gives the corresponding estimates for negative yy.

These bounds persist in the form needed below under small changes of η\eta and of the real contour coordinate. On bounded annuli in yy this follows by continuity. For large positive yy, write aj=θj(vR,η)∈(0,π)a_j=\theta_j(v_R,\eta)\in(0,\pi). The arguments of 2sin⁡(a1+iy/2)2\sin(a_1+iy/2) and 2sin⁡(aj−iy/2)2\sin(a_j-iy/2), j=2,3j=2,3, are respectively π/2−a1+O(e−y)\pi/2-a_1+O(e^{-y}) and aj−π/2+O(e−y)a_j-\pi/2+O(e^{-y}). Since 4a1+3a2+a3=2π4a_1+3a_2+a_3=2\pi, it follows that ∂yRe⁡G=−2π+O(e−y)\partial_y\operatorname{Re}G=-2\pi+O(e^{-y}), uniformly for nearby real vR,ηv_R,\eta. Conjugation treats the negative tail. The amplitude in (15.10) is O(e−|y|)O(e^{-|y|}) there. The global modulus bound from Lemma 15.2 transfers these estimates to the exact integrand, so all tails outside a fixed fold neighborhood are exponentially small in h−1h^{-1}. More explicitly, for each sufficiently small fixed δ>0\delta>0 there are mδ>0m_\delta>0 and Y0>δY_0>\delta, uniform in nearby real parameters, such that Re⁡G(vR+iy,η)≤−mδ−π(|y|−Y0)+,|y|≥δ.\operatorname{Re}G(v_R+iy,\eta) \le -m_\delta-\pi(|y|-Y_0)_+, \qquad |y|\ge\delta.

15.5 Airy localization and the first correction

Proof of Proposition 15.1. Write t=ηE−ηt=\eta_{\mathrm E}-\eta and λ=h1/3\lambda=h^{1/3}. Choose a fixed c>0c>0 and move the contour to v=v*+cλ+iy.v=v_*+c\lambda+iy. For all sufficiently small bb this deformation stays within the common pole-free strip. The tail bounds just proved make the horizontal closing segments vanish, so no residues or undetermined cycle coefficients enter.

At this displaced real point, Gvv=54cλ+OZ(λ2)>0G_{vv}=54c\lambda+O_Z(\lambda^2)>0 and Gvvvv=−6482+OZ(λ)<0G_{vvvv}=-648\sqrt2+O_Z(\lambda)<0. Taylor expansion in iyiy, with real derivatives at the real point, has real part −Gvvy2/2+Gvvvvy4/24+O(y6)-G_{vv}y^2/2+G_{vvvv}y^4/24+O(y^6). It gives constants c1,c2,δ>0c_1,c_2,\delta>0 such that Re⁡{G(v*+cλ+iy,η)−G(v*+cλ,η)}≤−c1λy2−c2y4,|y|≤δ.\begin{split} &\operatorname{Re}\{G(v_*+c\lambda+iy,\eta) -G(v_*+c\lambda,\eta)\}\\ &\quad \le -c_1\lambda y^2-c_2y^4, \qquad |y|\le\delta. \end{split}(15.15) The constants can be taken uniform for |ζ|≤Z|\zeta|\le Z. Outside this neighborhood use the previously established fixed tail gap and linear decay.

Now set x=v−v*=λ3Y,t=λ262ζ.x=v-v_*=\frac{\lambda}{3}Y,\qquad t=\frac{\lambda^2}{6\sqrt2}\zeta. The rescaled contour is upward with Re⁡Y=3c\operatorname{Re}Y=3c. The derivative table gives, through weighted order four, G(v*+x,ηE−t)=9x3−182tx+182t2−272x4+9tx2+RG(x,t),𝒜(v*+x,ηE−t)9/4=1+72x+O(x2+|t|).(15.16)\begin{aligned} G(v_*+x,\eta_{\mathrm E}-t) &=9x^3-18\sqrt2\,tx +18\sqrt2\,t^2-27\sqrt2\,x^4+9tx^2 +R_G(x,t),\\ \frac{\mathcal A(v_*+x,\eta_{\mathrm E}-t)}{9/4} &=1+7\sqrt2\,x+O(x^2+|t|). \end{aligned} Analyticity gives the explicit local bound |RG(x,t)|≤C(|x|5+|t||x|3+t2|x|+|t|3).|R_G(x,t)|\le C\bigl(|x|^5+|t||x|^3+t^2|x|+|t|^3\bigr). The exact quantum error in (15.9) is O(h)=O(λ3)O(h)=O(\lambda^3) and hence does not affect the first correction. Consequently, the rescaled integrand is 94eY3/3−ζY{1+λP(Y,ζ)+OZ(λ2)},\frac94\,e^{Y^3/3-\zeta Y} \left\{1+\lambda P(Y,\zeta)+O_Z(\lambda^2)\right\},(15.17) where the pointwise remainder is locally uniform and P(Y,ζ)=723Y−23Y4+ζ62Y2+24ζ2.P(Y,\zeta)= \frac{7\sqrt2}{3}Y-\frac{\sqrt2}{3}Y^4 +\frac{\zeta}{6\sqrt2}Y^2 +\frac{\sqrt2}{4}\zeta^2.(15.18)

For completeness, the integrated remainder is also OZ(λ2)O_Z(\lambda^2). On |Y|≤λ−1/12|Y|\le\lambda^{-1/12}, analytic Taylor remainders in (15.16), followed by exponentiation, give an error bounded by CZλ2(1+|Y|8)C_Z\lambda^2(1+|Y|^8), against the Gaussian |eY3/3−ζY|≤CZe−3c(Im⁡Y)2|e^{Y^3/3-\zeta Y}|\le C_Ze^{-3c(\operatorname{Im}Y)^2}. Indeed |RG|/h≤CZλ2(1+|Y|5)|R_G|/h\le C_Z\lambda^2(1+|Y|^5), and the square of the order-λ\lambda phase correction has degree eight. The growing cutoff makes both exponent remainders uniformly small. Equation (15.15) supplies a uniform Gaussian majorant for the exact rescaled integrand, since G(v*+cλ,η)/h=OZ(1)G(v_*+c\lambda,\eta)/h=O_Z(1). The part with λ−1/12<|Y|\lambda^{-1/12}<|Y| inside the fixed fold neighborhood is smaller than every power of λ\lambda; the global contour tail is exponentially small in h−1h^{-1}. This justifies integration of the expansion and its first correction.

With the chosen orientation, 12πi∫Re⁡Y=3ceY3/3−ζY⁡dY=Ai⁡(ζ);\frac1{2\pi i}\int_{\operatorname{Re}Y=3c} e^{Y^3/3-\zeta Y}\,\mathop{}\!\mathrm dY=\operatorname{Ai}(\zeta); this follows from [54, (9.5.4)] with its contour oriented from the lower ray to the upper ray. To deform those rays to Re⁡Y=3c\operatorname{Re}Y=3c, close at imaginary heights ±T\pm T. On each horizontal connector, with 3c≤x=Re⁡Y≤T/33c\le x=\operatorname{Re}Y\le T/\sqrt3, Re⁡(Y3/3−ζY)≤−89xT2+Zx,\operatorname{Re}(Y^3/3-\zeta Y) \le-\tfrac89xT^2+Zx, so the connector integrals vanish. Inserting YkY^k yields (−1)kAi⁡(k)(ζ)(-1)^k\operatorname{Ai}^{(k)}(\zeta). Using Ai⁡″(ζ)=ζAi⁡(ζ),Ai⁡(4)(ζ)=2Ai⁡′(ζ)+ζ2Ai⁡(ζ)\operatorname{Ai}''(\zeta)=\zeta\operatorname{Ai}(\zeta), \qquad \operatorname{Ai}^{(4)}(\zeta) =2\operatorname{Ai}'(\zeta) +\zeta^2\operatorname{Ai}(\zeta) in (15.18), all terms proportional to ζ2Ai\zeta^2\operatorname{Ai} cancel. The result is −32Ai⁡′(ζ)-3\sqrt2\,\operatorname{Ai}'(\zeta). Finally, ⁡dw/i=λ⁡dY/(6πib)\mathop{}\!\mathrm dw/i=\lambda\,\mathop{}\!\mathrm dY/(6\pi i b). Multiplication by 9/49/4 gives the coefficient 3λ/(4b)3\lambda/(4b) in (15.4). ◻

15.6 Numerical evidence and reproducibility status

The values below come from a new evaluation of the exact cleared integral (15.3), implemented in experiments/section15_quantum/. Write Qb(ζ)=4b3h1/3ℛ̂b(η),Qb(1)(ζ)=Ai⁡(ζ)−32h1/3Ai⁡′(ζ).Q_b(\zeta)=\frac{4b}{3h^{1/3}}\widehat{\mathcal R}_b(\eta), \qquad Q_b^{(1)}(\zeta)=\operatorname{Ai}(\zeta) -3\sqrt2\,h^{1/3}\operatorname{Ai}'(\zeta). The evaluator uses the exact centered identity (15.6). A finite expansion of DbD_b in derivatives of the cotangent has an explicit rational remainder bound uniform in a declared centered strip. This approximates the double-sine correction, not the Airy phase. All five logarithmic terms, with weights 4,3,1,2,−64,3,1,2,-6, are combined before exponentiation. The logarithms and the Lobachevsky primitive have the branches fixed above.

The outer Gauss–Legendre quadrature uses the upward contour v=v*+λ3(C+it),C>0,v=v_*+\frac{\lambda}{3}(C+it),\qquad C>0, with measure ⁡dw/i\mathop{}\!\mathrm dw/i; thus C=3cC=3c in the proof. Each of the seven parameter pairs described below is evaluated at 60 decimal digits with C=1C=1, |t|≤12|t|\le12, then at 90 digits with C=1C=1, |t|≤14|t|\le14, and again at 90 digits with C=5/4C=5/4 and two additional correction terms. The contribution beyond a shorter cutoff is recorded separately. The table rounds the 90-digit, C=1C=1 values to six decimals.

bb ζ\zeta Computed QbQ_b Airy Qb(1)Q_b^{(1)}
0.01250.0125 00 0.4590860.459086 0.4641640.464164
0.006250.00625 00 0.4225720.422572 0.4237790.423779
0.0031250.003125 00 0.3980470.398047 0.3983390.398339
0.01250.0125 11 0.2143330.214333 0.2024000.202400
0.006250.00625 11 0.1823160.182316 0.1775670.177567
0.0031250.003125 11 0.1638050.163805 0.1619240.161924

For the three ζ=1\zeta=1 rows, the newly computed values of (Qb−Qb(1))/h2/3(Q_b-Q_b^{(1)})/h^{2/3} are approximately 1.2080816841.208081684, 1.2113668191.211366819, and 1.2088787631.208878763. A negative transition parameter is also checked: Q1/160(−1)≈0.517966671856531Q_{1/160}(-1)\approx0.517966671856531. The largest observed 60/90-digit difference in these seven values is less than 4×10−574\times10^{-57}; changing the contour and correction order changes them by less than 1.3×10−911.3\times10^{-91}. These are comparisons between numerical runs, not guaranteed numbers of correct digits.

Direct quadrature of DbD_b and of the convergent real log⁡Sb\log S_b integral, together with the reflection and shift identities, checks the special-function evaluation independently of the correction expansion. A separate computation integrates the combined Barnes logarithm directly, using QUADPACK in ordinary double precision; its seven normalized values agree with the multiprecision calculation within 2×10−122\times10^{-12}. The rational bound controls correction-series truncation only. Its propagation uses a numerical absolute-integral estimate; the outer quadrature errors, sign tests, and tail-majorant formulas are evaluated without outward rounding. No total interval enclosure of the quantum integral is claimed.

The supplied draft’s evaluator and raw output remain unrecovered. Its six reported values are preserved in experiments/section15/historical-table.json. The new first value is 0.459086488736078952…0.459086488736078952\ldots, replacing the previously printed 0.4590870.459087 by 0.4590860.459086; the original rounding procedure is unknown. The other five values agree after rounding. This is new computational evidence with its own provenance, not a recovery of the missing original calculation.

The earlier companion experiments/section15/check.py checks the finite fold derivatives, the rational identity for Ψ′\Psi', and the first-correction cancellation in exact arithmetic with 2\sqrt2 adjoined. It also checks the Airy column at 80 and 120 digits against a separately coded ODE series [54, Sections 9.2 and 9.4]; its existing result remains a frozen record of those finite checks. Reproduction instructions for the new evaluator are in experiments/section15_quantum/README.md; its full result is written to artifacts/section15_quantum/result.json. Source identities, independent reviews, and generation records are collected in docs/execution/section15-analytic-review-2026-11-01/README.md. The analytic proof of Proposition 15.1 and this finite numerical evidence remain distinct.

15.7 Interpretation and scope

The correction to the earlier pole argument is substantive. The exact quantum integrand is smooth at the correct fold; the remaining real-bb resonances are an explicit scalar factor outside the integral. For example, at η=ηE\eta=\eta_{\mathrm E} the scalar factor has candidate resonances along b2=3ηE−π2πm,m=1,2,….b^2=\frac{3\eta_{\mathrm E}-\pi}{2\pi m}, \qquad m=1,2,\ldots. The numerator in (15.3) is nonzero for sufficiently small bb, uniformly in each fixed physical window 0≤ζ≤Z0\le\zeta\le Z: the continuous positive function Ai⁡(ζ)\operatorname{Ai}(\zeta) has a positive minimum on [0,Z][0,Z], and the additive correction and error tend uniformly to zero. Thus zeros of the squared sine give genuine double poles of the original normalization in this window, including all sufficiently large mm in the displayed sequence. For negative ζ\zeta, the additive asymptotic remains uniform even at zeros of Ai\operatorname{Ai}; no uniform noncancellation or relative-error assertion is made there. The cleared quantity has the uniform asymptotic in the proposition even through these resonances.

In geometric terms, ζ=A23h2/3+O(A2h2/3),A≍b4/3.\zeta=\frac{A}{2\sqrt3\,h^{2/3}} +O\!\left(\frac{A^2}{h^{2/3}}\right), \qquad A\asymp b^{4/3}. The decaying Airy branch selected by the contour agrees with the decaying volume exponential: its classical saddle exponent is −2W/h=−W/(πb2)-2W/h=-W/(\pi b^2). The proposition is uniform for bounded ζ\zeta; it does not, by itself, justify taking ζ→∞\zeta\to\infty simultaneously with b→0b\to0 or keeping a nonzero tetrahedral volume fixed. Those matching limits require additional estimates.

This proves a quantum transition for one specified regular family, beyond the classical cubic calculation. Extension to arbitrary nondegenerate Euclidean tetrahedral shapes, comparison of normalizations used in a global state integral, and gluing into a topological invariant remain separate problems. In particular no new case of the colored-Jones volume conjecture, and no identification of the integrated quantum measure with the cone-metric measure, follows from this proposition alone.