ScalingStacks

0PCA

Remark 8.1.6. Assume ξ\xi is terminal for (Z,M)(Z,M). Consider f:Z→∼Zf:Z\mathrel{\mathop{\kern 0.0pt\to}\limits^{\sim}}Z an isomorphism of curves fixing MM. Note that f∘ξf\circ\xi is terminal for (Z,M)(Z,M) and the map ff induces an isomorphism Lξ∙→∼Lf∘ξ∙L_{\xi}^{\bullet}\mathrel{\mathop{\kern 0.0pt\to}\limits^{\sim}}L_{f\circ\xi}^{\bullet}.

Consider now another injective morphism of curves ξ′:𝐑>0→Z\xi^{\prime}:{\mathbf{R}}_{>0}\to Z such that ξ′\xi^{\prime} is terminal for (Z,M)(Z,M). Assume there is a connected open subset UU of ZuZ_{u} containing ξ⁡(𝐑>0)¯\overline{\xi({\mathbf{R}}_{>0})} and ξ′​(𝐑>0)¯\overline{\xi^{\prime}({\mathbf{R}}_{>0})} and assume the canonical orientations on ξ⁡(𝐑>0)\xi({\mathbf{R}}_{>0}) and ξ′​(𝐑>0)\xi^{\prime}({\mathbf{R}}_{>0}) extend to an orientation of UU. There is an isomorphism of curves f:Z→∼Zf:Z\mathrel{\mathop{\kern 0.0pt\to}\limits^{\sim}}Z fixing Z∖UZ\setminus U such that ξ′=f∘ξ\xi^{\prime}=f\circ\xi. It induces an isomorphism Lξ∙→∼Lξ′∙L_{\xi}^{\bullet}\mathrel{\mathop{\kern 0.0pt\to}\limits^{\sim}}L_{\xi^{\prime}}^{\bullet}, and that isomorphism does not depend on the choice of ff.

Original mathematics by the credited authors. Source collection and HTML conversion remain in progress.

Andrew Manion, Raphael Rouquier

Original source: arXiv:2009.09627v2