In his book on noncommutative geometry, Connes constructed a differential graded algebra out of a spectral triple. Lack of monoidality of this construction is investigated. We identify a suitable monoidal subcategory of the category of spectral triples and show that when restricted to this subcategory the construction of Connes is monoidal. Richness of this subcategory is exhibited by establishing a faithful endofunctor to this subcategory.

中文翻译：

---

Connes 微积分的乘法性

在他关于非对易几何的书中，Connes 从谱三元组构造了一个微分分级代数。研究了这种结构缺乏单一性。我们确定了光谱三元组类别的一个合适的单面子类别，并表明当限制在这个子类别时，Connes 的构造是单面的。通过为该子类别建立一个忠实的内函子来展示该子类别的丰富性。