We define torsion pairs for quasi-abelian categories and give several characterisations. We show that many of the torsion theoretic concepts translate from abelian categories to quasi-abelian categories. As an application, we generalise the recently defined algebraic Harder-Narasimhan filtrations to quasi-abelian categories.

中文翻译：

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扭转对和拟阿贝尔类别

我们为准阿贝尔类别定义了扭转对，并给出了一些特征。我们证明了许多扭转理论概念都从阿贝尔类别转换为准阿贝尔类别。作为一种应用，我们将最近定义的代数Harder-Narasimhan滤波推广到准阿贝尔分类。