Week 5

Posted on 2025-09-29

materials

topics

This week, we’ll talk about the following:

  • for an ideal \(I\) of a ring \(R\), the quotient group \(R/I\) has the structure of a ring

  • after that, the goal for the week will be to introduce analogues of basic notions from linear algebra, but where the scalars are taken from an arbitrary commutative ring

  • the notion of a category, and explain why initial and terminal objects in a category are unique

  • the notion of a product and a co-product in a category

  • the notion of a module over a commutative ring

  • the notion of the direct sum of modules (a co-product in the category of modules).

  • the notion of a free module, meaning module with a basis.