W型绳轮

Sheaf Theory through Examples (Abridged Version)

This book provides an inviting tour through sheaf theory, from the perspective of applied category theory and pitched at a less specialized audience than is typical with introductions to sheaves. The book makes it as easy as possible for the reader new to sheaves, by motivating and developing the theory via a broad range of concrete examples and explicit constructions, including applications to n-colorings of graphs, satellite data, chess problems, Bayes nets, musical performance, complexes, and more. Included is an extended first chapter introducing and motivating all the necessary category-t…

Derived Categories of Coherent Sheaves and Triangulated Categories of Singularities

In this paper we establish an equivalence between the category of graded D-branes of type B in Landau-Ginzburg models with homogeneous superpotential W and the triangulated category of singularities of the fiber of W over zero. The main result is a theorem that shows that the graded triangulated category of singularities of the cone over a projective variety is connected via a fully faithful functor to the bounded derived category of coherent sheaves on the base of the cone. This implies that the category of graded D-branes of type B in Landau-Ginzburg models with homogeneous superpotential W …

Dynamical Systems and Sheaves

A categorical framework for modeling and analyzing systems in a broad sense is proposed. These systems should be thought of as `machines' with inputs and outputs, carrying some sort of signal that occurs through some notion of time. Special cases include continuous and discrete dynamical systems (e.g. Moore machines). Additionally, morphisms between the different types of systems allow their translation in a common framework. A central goal is to understand the systems that result from arbitrary interconnection of component subsystems, possibly of different types, as well as establish conditio…

关于n型同伦理论

On the homotopy theory of n-types

简单（预）层上的n-截断模型结构被描述为具有弱等价映射，其在某些同伦层上诱导同构仅达到n次。从一个Jardine的中间模型结构，我们通过Bousfield-Friedlander本地化构建这样一个n型模型结构，并表现出有用的生成集的平凡cofibrations。这些类别中的内射双射对象被称为n-超堆栈。因此，整个设置可以被看作是更高的超栈同伦理论的描述。更重要的是，我们构造类似的n-截断单纯广群，并证明了这些设置之间的Quillen等价。利用单纯广群胚的（n-1）-型预层，我们得到了n-型单纯预层的分类。我们的分类适用于一般的n。因此，这也可以看作是（弱）高级群胚的（预）层的同伦理论。

可微层的同伦论

The homotopy theory of differentiable sheaves

本文通过将流形嵌入可微层∞-topos，证明流形形状与经典同伦型一致，构造以形状等价为弱等价的模型结构，并给出代数拓扑经典定理的新证明。