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arXiv 1608.04025math.CO
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有序单纯复形的拟拟阵类

Quasi-matroidal classes of ordered simplicial complexes

Jose Alejandro Samper

摘要:

我们引入了有序单纯复形的拟拟阵类的概念:在有序单纯复形的景观中拟阵隐态的想法的近似。拟拟阵类包含纯移位单纯复形和有序拟阵独立复形。其基本性质是:如果一个固定的单纯复形对于它的顶点集的每一个序都属于这个类,那么它是拟阵独立复形。此类类的一些例子隐含地出现在拟阵理论文献中。我们介绍了各种这样的类,突出不同方面的拟阵理论和它的相似之处,转移单纯复形理论。例如,我们解除研究的对象,如Tutte多项式和nbc复杂的准拟阵类,使我们能够定义这样的对象的移位复杂。此外,一些拟拟阵类可以用归纳技术来处理,而这些技术不能直接应用于拟阵理论。作为一个例子,我们提供了一个合适的设置重新制定和扩展猜想的斯坦利约$h$ -向量拟阵,预计是易于处理的技术,是遥不可及的拟阵单独。这个新猜想适用于纯移位单纯复形和秩不超过4的拟阵。

英文摘要:

We introduce the notion of a quasi-matroidal class of ordered simplicial complexes: an approximation to the idea of a matroid cryptomorphism in the landscape of ordered simplicial complexes. A quasi-matroidal class contains pure shifted simplicial complexes and ordered matroid independence complexes. The essential property is that if a fixed simplicial complex belongs to this class for every ordering of its vertex set, then it is a matroid independence complex. Some examples of such classes appear implicitly in the matroid theory literature. We introduce various such classes that highlight different apsects of matroid theory and its similarities with the theory of shifted simplicial complexes. For example, we lift the study of objects like the Tutte polynomial and nbc complexes to a quasi-matroidal class that allows us to define such objects for shifted complexes. Furthermore, some of the quasi-matroidal classes are amenable to inductive techniques that can't be applied directly in the context of matroid theory. As an example, we provide a suitable setting to reformulate and extend conjecture of Stanley about $h$-vectors of matroids which is expected to be tractable with techniques that are out of reach for matroids alone. This new conjecture holds for pure shifted simplicial complexes and matroids of rank up to 4.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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