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In the graph, each vertex correspond to an endomorphism of abelian varieties in the isogeny class and each edge correspond to an inclusion.

For each endomorphism ring $S$, we use the following notation $[\mathrm{index}]^{\#\mathrm{weak}\cdot \#\mathrm{Pic}}_i$ :

  • $\mathrm{index}$ is the index of the inclusion (of additive groups) $S\subseteq \mathcal{O}$, where $\mathcal{O}$ is the maximal order of the étale $\mathbb{Q}$-algebra $\mathbb{Q}[F]$;

  • $i$ is a counter that uniquely identifies the order $S$ among all the overorders of $\mathbb{Z}[F,V]$ with index in $\mathcal{O}$ equal to $\mathrm{index}$. See also isogeny label.

  • $\#\mathrm{weak}$ is the number of weak equivalence classes represented by fractional $\mathbb{Z}[F,V]$-ideals $I$ with multiplicator ring equal to $S$, that is, satisfying $(I:I)=S$; if $S$ is Gorenstein, that is, $\#\mathrm{weak} = 1 $ this number is omitted from the notation.

  • $\#\mathrm{Pic}$ is the size of the Picard groups of $S$, that is, the number of invertible fractional $S$-ideals.

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  • Review status: beta
  • Last edited by David Roe on 2025-06-30 19:27:50
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