ScalingStacks

Proof. [04A9]

Original official author HTML, exact retained edition. Historical TeX conversion verdicts remain unchanged. Cited-edition alignment and mathematical self-containment are not assessed.

Complete original source context · Original author HTML

Proof.

We modify the proof of Lemma 3.5 and Cor. 3.6. We think of the corner qq as the origin in the upper half plane model. Without loss of generality vnv_{n} is the ℝ\mathbb{R}-translation vector field of the holomorphic strip. Then the leading order asymptotic is

vk=(ak​1zϕ1/π−1,…,ak​nzϕn/π−1)+O(1),k=1,2,…n−1,v_{k}=(a_{k1}z^{\phi_{1}/\pi-1},\ldots,a_{kn}z^{\phi_{n}/\pi-1})+O(1),\quad k=1,2,\ldots n-1,

and

vn=(an​1​zϕ1/π,…,an​n​zϕn/π)+O⁡(z).v_{n}=(a_{n1}z^{\phi_{1}/\pi},\ldots,a_{nn}z^{\phi_{n}/\pi})+O(z).

hence

Ω⁡(v1,…​vn)=z(∑ϕk)/π−n+1​(det(ak​j)+o⁡(1)),\Omega(v_{1},\ldots v_{n})=z^{(\sum\phi_{k})/\pi-n+1}(\det(a_{kj})+o(1)),

The excess vanishing order is ≥1−n\geq 1-n, where negative order stands for poles. By the index formula (23) for the ordinary linearized Cauchy-Riemann equation, we have

deg⁡q−deg⁡p≥1−n+n=1,\deg q-\deg p\geq 1-n+n=1,

and equality forces Ω⁡(v1,…​vn)\Omega(v_{1},\ldots v_{n}) to have no interior zero, no boundary zero, minimal zero at pp, and det(ak​j)≠0\det(a_{kj})\neq 0 at qq. The argument in Cor. 3.6 shows v1,…​vn,vnzv_{1},\ldots v_{n},\frac{v_{n}}{z} span the real vector space of first order deformations in W1,2;πW^{1,2;\pi}. In particular, the only first order deformation which decays at qq is the ℝ\mathbb{R}-translation vector field. Thus the cokernel to the ordinary linearized Cauchy-Riemann operator vanishes, and the moduli space is regular. ∎

Original mathematics by the credited authors. Source-backed reader collection; mathematical self-containment is not assessed.