ScalingStacks

Proof. [04P8]

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.

By the proof of Theorem B and Proposition 1.5.2 we have the following diagram:

𝔛D{\lx@inpgf@ignorespaces\mathfrak{X}_{D}}𝔑D{\lx@inpgf@ignorespaces\mathfrak{N}_{D}}Star⁡(vD){\lx@inpgf@ignorespaces\Star(v_{D})}Int⁡(Σ1){\lx@inpgf@ignorespaces\mathrm{Int}(\Sigma_{1})}≃\simeqρ𝒳{\rho_{\mathscr{X}}}val\val≃\simeqφ\varphi

where the upper arrow is an isomorphism of analytic spaces, and the lower one a homeomorphism. Here 𝔛D\mathfrak{X}_{D} and 𝔑D\mathfrak{N}_{D} are the generic fibers (in the sense of Berkovich) of the formal completions 𝒳/D^\widehat{\mathscr{X}_{/D}} and 𝒩/D^\widehat{\mathscr{N}_{/D}} respectively, and Int⁡(Σ1)\mathrm{Int}(\Sigma_{1}) denotes the interior of the polyhedral complex Σ1\Sigma_{1} obtained by intersecting the fan Σ^⊂Nℝ×ℝ\hat{\Sigma}\subset N_{\mathbb{R}}\times\mathbb{R} of the normal bundle of DD in 𝒳\mathscr{X} with Nℝ×{1}N_{\mathbb{R}}\times\{1\}. In particular, Int⁡(Σ1)\mathrm{Int}(\Sigma_{1}) is embedded in ΣD≃Nℝ≃ℝn\Sigma_{D}\simeq N_{\mathbb{R}}\simeq\mathbb{R}^{n}, the polyhedral decomposition of Star⁡(vD)\Star(v_{D}) is the same of ΣD\Sigma_{D}, and the vertex vDv_{D} corresponds to the origin. By Section 1.6, the integral affine structure on Star⁡(vD)\Star(v_{D}) is the pullback via φ\varphi of the integral affine structure on ΣD\Sigma_{D}, and this concludes the proof. ∎

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