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Simpson Jacobians of reducible curves

Ana Cristina Lopez
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Abstract

For any projective curve $X$ let $\bar{M}^d(X)$ be the Simpson moduli space of pure dimension one rank 1 degree $d$ sheaves that are semistable with respect to a fixed polarization $H$ on $X$. When $X$ is a reduced curve the connected component of $\bar{M}^d(X)$ that contains semistable line bundles can be considered as the compactified Jacobian of $X$. In this paper we give explicitly the structure of this compactified Simpson Jacobian for the following projective curves: tree-like curves and all reduced and reducible curves that can appear as Kodaira singular fibers of an elliptic fibration, that is, the fibers of types $III$, $IV$ and $I_N$ with $N\geq 2$

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Ana Cristina Lopez. 2004-10-18. Simpson Jacobians of reducible curves. https://arxiv.org/abs/math/0410393

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