论文标题
在Noetherian代数,Schur函子和Hemmer-Nakano尺寸
On Noetherian algebras, Schur functors and Hemmer-Nakano dimensions
论文作者
论文摘要
表示理论中的重要联系是由具有有限全球尺寸的发电机基因器的内态代数来解决有限维代数的产生。例如,奥斯兰德的信件,古典schur- weyl二元性和苏格尔的struktursatz。在这里,分辨率的模块类别和要解决的代数的模块类别是通过称为Schur函数的确切函数链接的。在本文中,我们研究了如何衡量(投影)Noetherian代数,$ b $的模块类别之间的连接质量,以及与$ b $相关的符合质量的固定器代数的内态代数的模块类别,这些代数是分裂的Quasi-hersedpartial Noetherian代数。特别是,我们有兴趣发现,如果存在,则是最高程度的$ n $,以便从$ b $的rouquier的意义上讲,发电机 - 生成器的内态代数为$ n $ faithful的封面提供。 $ n $被称为标准模块的Hemmer-Nakano尺寸。我们证明,标准模块的Hemmer-nakano尺寸相对于从一个字段的分裂最高权重类别到有限维代数$ b $的模块类别的Schur函子的Hemmer-Nakano尺寸以上是$ b $的非异态简单模块的数量。我们建立了如何减少积分设置中Hemmer-Nakano尺寸的计算,以计入有限维代数上Hemmer-Nakano尺寸的计算。该理论使我们能够使用相对显性维度从有限维情况中的积分设置中得出Schur代数和BGG类别O的结果。我们展示了BGG类别块的变形的几种结构性o,建立了Soergel的Struktursatz的积分版本。我们表明,组合Soergel的函子的变形具有比经典效能更好的同源性能。
Important connections in representation theory arise from resolving a finite-dimensional algebra by an endomorphism algebra of a generator-cogenerator with finite global dimension; for instance, Auslander's correspondence, classical Schur--Weyl duality and Soergel's Struktursatz. Here, the module category of the resolution and the module category of the algebra being resolved are linked via an exact functor known as Schur functor. In this paper, we investigate how to measure the quality of the connection between module categories of (projective) Noetherian algebras, $B$, and module categories of endomorphism algebras of generators-relative cogenerators over $B$ which are split quasi-hereditary Noetherian algebras. In particular, we are interested in finding, if it exists, the highest degree $n$ so that the endomorphism algebra of a generator-cogenerator provides an $n$-faithful cover, in the sense of Rouquier, of $B$. The degree $n$ is known as Hemmer-Nakano dimension of the standard modules. We prove that the Hemmer-Nakano dimension of standard modules with respect to a Schur functor from a split highest weight category over a field to the module category of a finite-dimensional algebra $B$ is bounded above by the number of non-isomorphic simple modules of $B$. We establish methods how to reduce computations of Hemmer-Nakano dimensions in the integral setup to computations of Hemmer-Nakano dimensions over finite-dimensional algebras. This theory allows us to derive results for Schur algebras and the BGG category O in the integral setup from the finite-dimensional case using relative dominant dimension. We exhibit several structural properties of deformations of the blocks of the BGG category O establishing an integral version of Soergel's Struktursatz. We show that deformations of the combinatorial Soergel's functor have better homological properties than the classical one.