Quotienting a Category by an Object: Explained

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SUMMARY

The discussion clarifies the concept of quotienting a category by an object, specifically within the context of the category I, a full subcategory of Top. It distinguishes between a quotient and a "slice category," which is a specific type of "comma category." The category E/A is defined by objects as arrows of the form B --> A and arrows as commutative triangles with a distinguished vertex A. This precise definition aids in understanding the structure and relationships within categorical frameworks.

PREREQUISITES
  • Understanding of category theory concepts, particularly "comma categories."
  • Familiarity with the structure of full subcategories, specifically in the context of Top.
  • Knowledge of arrows and morphisms in category theory.
  • Basic grasp of commutative diagrams and their significance in categorical contexts.
NEXT STEPS
  • Study the properties and applications of "comma categories" in advanced category theory.
  • Explore the concept of "slice categories" and their role in categorical constructions.
  • Learn about the implications of coproducts in the context of category I.
  • Investigate the relationships between arrows and morphisms in various categorical frameworks.
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Mathematicians, category theorists, and computer scientists interested in advanced categorical concepts and their applications in topology and algebra.

fallgesetz
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What does it mean to quotient a category by an object of the category?

In particular, the problem in front of me specifies the category I ( a full subcategory of Top which is compact, contains coproducts, and the one point space), an object X of I, and asks me to do stuff with I/X.
 
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This isn't a quotient, but a "slice category", a particular kind of "comma category".

Given any category E and object A, the category E/A is defined by:
. The objects of E/A are arrows of C of the form B --> A
. The arrows of E/A are commutative triangles of C with a distinguished vertex A (This arrow "points" in the same direction as the edge opposite A)

Or a more algebraic description
. Objects are arrows f of E such that codom(f) = A
. HomE/A(f,g) is the class of arrows h of E such that gh=f
 

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