ScalingStacks

Proof. [04XL]

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Proof.

The equality Δ⁡(A)=Sk⁡(A)\Delta(A)=\mathrm{Sk}(A) is proven in [HN17, 4.3.2]. Let 𝒫\mathscr{P} be a Künnemann-Mumford model for AA over RR. Then, by definition, 𝒫\mathscr{P} is an snc-model, and thus certainly good and dlt. It is shown in [HN17, 5.1.7] that 𝒫\mathscr{P} is minimal.

Let 𝒫~\widetilde{\mathscr{P}} be a regular relatively complete model of TT as in [Kü98, 2.11] such that the formal tt-adic completion of 𝒫\mathscr{P} arises as a quotient of the formal tt-adic completion of 𝒫~\widetilde{\mathscr{P}} under an action of the period lattice. Then, by construction, 𝒫~\widetilde{\mathscr{P}} is a torus embedding of TT over RR, and we have a commutative diagram

Tan\textstyle{T^{\mathrm{an}}\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces}π\scriptstyle{\pi}ρT\scriptstyle{\rho_{T}}ρ𝒫~\scriptstyle{\rho_{\widetilde{\mathscr{P}}}}Δ⁡(T)\textstyle{\Delta(T)\ignorespaces\ignorespaces\ignorespaces\ignorespaces}Aan\textstyle{A^{\mathrm{an}}\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces\ignorespaces}ρA\scriptstyle{\rho_{A}}ρ𝒫\scriptstyle{\rho_{\mathscr{P}}}Δ⁡(A).\textstyle{\Delta(A).}

Thus in order to prove that ρ𝒫=ρA\rho_{\mathscr{P}}=\rho_{A}, it suffices to observe that ρ𝒫~=ρT\rho_{\widetilde{\mathscr{P}}}=\rho_{T} by Example 3.5. ∎

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