Category theory MOC

Category-vector space analogy

There is a striking, albeit informal, correspondence between the basic concepts of category theory and linear algebra. The following table, based on 2011. Introduction to representation theory, ยง7.6, is a summary.

Category theoryLinear algebra
category ๐–ขvector space ๐‘‰
hom-set ๐–ข(๐‘‹,๐‘Œ)nondegenerate bilinear form
โŸจ๐‘ฅ,๐‘ฆโŸฉ
opposite categoryopposite inner product
๐–ฒ๐–พ๐—ground field ๐•‚
full subcategorynondegenerate subspace
functor ๐น :๐–ข โ†’๐–ฃlinear map ๐‘“ :๐‘‰ โ†’๐‘Š
presheaflinear form
Yoneda lemmanondegeneracy
representable functorrepresentable form
adjoint functoradjoint operator


#state/tidy | #lang/en | #SemBr