论文标题
第二个下降阻塞和gerbes
The second descent obstruction and gerbes
论文作者
论文摘要
我们扩展了种类的合理点和共同体学障碍的概念到类别中的类别。我们还建立了Torsors的普遍后裔理论。然后，我们解释了阿贝尔滑轮的第二次共同体学以凝视剂的分类点的障碍，这是托尔索尔（Torsors）的类似物。作为一种应用，我们构建了一些不大于下降阻塞的复合障碍物。我们还提出了一些新型的障碍物，包括衍生的障碍物，这些阻塞在产品下具有良好的行为，并且也不大于下降阻塞。
We extend the notion of rational points and cohomological obstructions on varieties to categories fibred in groupoids. We also establish the generalized theory of descent by torsors. Then we interpret the obstruction given by the second cohomology of abelian sheaves in terms of categorical points of gerbes, analogue to descent by torsors. As an application, we construct some composite obstructions not larger than the descent obstruction. We also propose some new kinds of obstructions including the derived obstruction, which has good behavior under a product and is also not larger than the descent obstruction.
