Tensor Product as a Universal Object (Category Theory & Module Theory)

1 · Admiraldesvl · Jan. 19, 2021, 9:25 a.m.
IntroductionIt is quite often to see direct sum or direct product of groups, modules, vector spaces. Indeed, for modules over a ring $R$, direct products are also direct products of $R$-modules as well. On the other hand, the direct sum is a coproduct in the category of $R$-modules.But what about tensor products? It is some different kind of product but how? Is it related to direct product? How do we write a tensor product down? We need to solve this question but it is not a good idea to dig int...