ScalingStacks

Corollary 2.9 . [059K]

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Corollary 2.9.

Let RR be a stratum of 𝔛~β€²β€²\tilde{\mathfrak{X}}^{\prime\prime} corresponding to the open face Ο„\tau of 𝔇\mathfrak{D}.

  1. (a)

    dim(Ο„)=codim⁑(R,𝔛~β€²β€²)\dim(\tau)=\codim(R,\tilde{\mathfrak{X}}^{\prime\prime}).

  2. (b)

    S:=ΞΉ~​(R)S:=\tilde{\iota}(R) is a stratum of 𝔛~\tilde{\mathfrak{X}}.

  3. (c)

    R​→ι~​SR\overset{\tilde{\iota}}{\rightarrow}S is a fibre bundle with fibre TT where TT is the dim(R)βˆ’dim(S)\dim(R)-\dim(S) dimensional torus orbit from the proof of Proposition 2.8.

  4. (d)

    Every stratum of 𝔛~β€²β€²\tilde{\mathfrak{X}}^{\prime\prime} is smooth.

  5. (e)

    The closure RΒ―\bar{R} is the union of all strata of 𝔛~β€²β€²\tilde{\mathfrak{X}}^{\prime\prime} corresponding to open faces Οƒ\sigma of 𝔇\mathfrak{D} with Ο„βŠ†ΟƒΒ―\tau\subseteq\bar{\sigma}.

  6. (f)

    For an irreducible component YY of 𝔛~β€²β€²\tilde{\mathfrak{X}}^{\prime\prime}, let ΞΆY\zeta_{Y} be the unique point of 𝔛an\mathfrak{X}^{\textup{an}} with reduction equal to the generic point of YY. Then Y↦΢YY\mapsto\zeta_{Y} is a bijection between the irreducible components of 𝔛~β€²β€²\tilde{\mathfrak{X}}^{\prime\prime} and the vertices of 𝔇\mathfrak{D}.

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