In mathematics, a sheaf (pl.: sheaves) is a tool for systematically tracking data (such as sets, abelian groups, rings) attached to the open sets of a topological space and defined locally with regard to them.
In this paper we will first take a look at sheaves on graphs, be- cause they are finite and discrete and then later build intuition about how to build sheaves on topological spaces.
2024年7月19日 · Figuring out what sheaves are possible gives mathematicians a way to probe the structure of the underlying space, just as knowing which plants grow in a particular type of soil gives you information about that soil.
Part 1. Sheaves 1. Sheaves: the lightning tour 1.1. Category theory. Sheaf theory requires some category theory, as summarized in Appendix A. Don’t try to read it all at once. I have added references to this section as needed. 1.2. Let Rbe a commutative ring (with 1). Let Xbe a topological space.
2022年7月18日 · There are many sorts of things that can happen on a space, and these are the sheaves: a sheaf on a space is roughly “a sort of thing that can happen on the space.” If we want to think about points or regions from the sheaf perspective, we would consider them as different points of view on what’s happening.
2024年12月15日 · Specifically, a presheaf F on a topological space X is a sheaf if it satisfies the following conditions: 1. if U is an open set, if {U_i} is an open covering of U and if s in F (U) is an element such that s|_ (U_i)=0 for all i, then s=0. 2.
The tool we will use for managing the regular functions on the space is called a sheaf. Sheaves are general tools whose purpose is to de ne collections objects in some category (e.g. Sets, Groups, Rings, or Modules) which are stitched together topologically.
LECTURE NOTES ON SHEAVES AND PERVERSE SHEAVES MARK GORESKY version of October 10, 2021 Contents Part 1. Sheaves 3 1. Sheaves: the lightning tour 3 2. Cohomology 8 3. Complexes of sheaves 13 4. Godement and Cech 18 5. The sheaf of chains 21 6. Homotopy and injectives 22 7. The derived category 25 8. Strati cations 32 9. Constructible sheaves and ...
2022年2月3日 · I hope this paper provides insight, intuition, and helpful examples of why sheaves are such powerful tools in both math and science. Subjects: Algebraic Geometry (math.AG) ; Algebraic Topology (math.AT)