ScalingStacks

Example 2.50 . [02K1]

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Example 2.50.

Let BB be a irreducible projective variety over a field kk, which is regular in codimension 1, and LL an ample line bundle on BB. Set 𝕂=k⁑(B)\mathbb{K}=k(B). For a prime divisor vv on BB and Ξ±βˆˆπ•‚Γ—\alpha\in\mathbb{K}^{\times}, we denote by ordv⁑(Ξ±){\operatorname{ord}}_{v}(\alpha) the order of Ξ±\alpha at vv. Fix a constant c>1c>1 and denote by 𝔐𝕂\mathfrak{M}_{\mathbb{K}} the set of prime divisors on BB. For each vβˆˆπ”π•‚v\in\mathfrak{M}_{\mathbb{K}}, the corresponding absolute value and weight are defined as

|Ξ±|v=cβˆ’ordv⁑(Ξ±),nv=degL⁑(v).|\alpha|_{v}=c^{-{\operatorname{ord}}_{v}(\alpha)},\quad n_{v}=\deg_{L}(v).

Then (𝕂,𝔐𝕂)(\mathbb{K},\mathfrak{M}_{\mathbb{K}}) is an adelic field. Moreover, 𝕂\mathbb{K} satisfies the product formula, since the degree of a principal divisor is zero,

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