In this paper we study the existence of sections of universal bundles on rational homogeneous varieties–called nestings–classifying them completely on rational homogeneous varieties G/P in the case where G is a simple group of classical type and P is a parabolic subgroup of G. In particular we show that, under this hypothesis, nestings do not exist unless there exists a proper algebraic subgroup of the automorphism group acting transitively on the base variety.

中文翻译：

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有理同质变量的嵌套

在本文中，我们研究在有理同质变种上通用束的部分（称为嵌套）的存在，在G是经典类型的简单群且P是G的抛物子群的情况下，将它们完全按照有理同质变种G / P进行分类。。特别地，我们表明，在这种假设下，除非存在自同构群的一个适当的代数子群，该母体在传递给基变体时起作用，否则不存在嵌套。