Three decades ago Cornalba and Harris proved a fundamental positivity result for divisor classes associated to families of stable curves. In this paper we establish an analogous positivity result for divisor classes associated to families of stable differentials.

中文翻译：

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微分层上除数类的正性

三年前，Cornalba和Harris证明了与稳定曲线族相关的除数类的基本阳性结果。在本文中，我们为与稳定微分族相关的除数类建立了一个类似的阳性结果。