ScalingStacks

Proof. [018L]

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Proof.

The map τ:𝔻¯r→ℳ⁡(Ar)\tau\colon\overline{{\mathbb{D}}}_{r}\to{\mathcal{M}}(A_{r}) given by (A.1) is clearly well defined. It is also continuous on 𝔻¯r∗\overline{{\mathbb{D}}}^{*}_{r}. To prove continuity at 00, we note that for each f∈Arf\in A_{r}, we can write fhol=zord0⁡(f)​uf^{\operatorname{hol}}=z^{\operatorname{ord}_{0}(f)}u, where uu is a continuous function on 𝔻¯r\overline{{\mathbb{D}}}_{r} that is holomorphic on 𝔻r{\mathbb{D}}_{r} with u⁡(0)≠0u(0)\neq 0. As a consequence, we get limz→0log⁡|fhol​(z)|∞log⁡|z|∞=ord0⁡(f)\lim_{z\to 0}\frac{\log|f^{\operatorname{hol}}(z)|_{\infty}}{\log|z|_{\infty}}=\operatorname{ord}_{0}(f).

Now, for each ρ∈(0,1]\rho\in(0,1], λ−1​(ρ)⊂Chyb​(r)\lambda^{-1}(\rho)\subset C_{\mathrm{hyb}}(r) can be identified with the circle of radius rr with respect to the absolute value |⋅|∞ρ|\cdot|_{\infty}^{\rho}, while λ−1​(0)\lambda^{-1}(0) is the non-Archimedean absolute value r−ord0r^{-\operatorname{ord}_{0}} on ℂ⁡((t)){\mathbb{C}}(\!({t})\!). This proves that the map τ\tau above is bijective, and hence a homeomorphism by compactness. ∎

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