Portal:Category theory

From Wikipedia, the free encyclopedia

Category theory

Commutative diagram for morphism.svg

In mathematics, category theory deals in an abstract way with mathematical structures and relationships between them. Categories now appear in most branches of mathematics and in some areas of theoretical computer science and mathematical physics, and have been a unifying notion. Categories were first introduced by Samuel Eilenberg and Saunders Mac Lane in 1942-1945, in connection with algebraic topology.

The term "abstract nonsense" has been used by some critics to refer to its high level of abstraction, compared to more classical branches of mathematics. Homological algebra is category theory in its aspect of organising and suggesting calculations in abstract algebra. Diagram chasing is a visual method of arguing with abstract 'arrows'. Topos theory is a form of abstract sheaf theory, with geometric origins, and leads to ideas such as pointless topology.

Selected Article

In mathematics, a category is a fundamental and abstract way to describe mathematical entities and their relationships. A category is composed of a collection of abstract "objects" of any kind, linked together by a collection of abstract "arrows" of any kind that have a few basic properties (the ability to compose the arrows associatively and the existence of an identity arrow for each object). Many well-known categories are conventionally identified by a short capitalized word or abbreviation in bold or italics such as Set (category of sets) or Ring (category of rings).

...Other articles

Selected Biography

Saunders Mac Lane (4 August 1909, Taftville, Connecticut – 14 April 2005, San Francisco) was an American mathematician who cofounded category theory with Samuel Eilenberg. Their original motivation was homology theory and led to the formalization of what is now called homological algebra. His most recognized work in category theory is the textbook Categories for the Working Mathematician (1971).


Selected Picture

Functor cone (extended).svg

In category theory, a limit of a diagram is defined as a cone satisfying a universal property. Products and equalizers are special cases of limits. The dual notion is that of colimit.

Did you know?


Things to do


Category theory on Wikinews     Category theory on Wikiquote     Category theory on Wikibooks     Category theory on Wikisource     Category theory on Wiktionary     Category theory on Wikimedia Commons
News Quotations Manuals & Texts Texts Definitions Images & Media

Purge server cache

Retrieved from "https://en.wikipedia.org/w/index.php?title=Portal:Category_theory&oldid=644091357"
This content was retrieved from Wikipedia : http://en.wikipedia.org/wiki/Portal:Category_theory
This page is based on the copyrighted Wikipedia article "Portal:Category theory"; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA