Useful Links
Mathematics
Abstract Algebra
Modules
Definition and Examples
Formal Definition
Modules over a ring
Key properties and axioms
Examples of Modules
\( \mathbb{Z}^n \) as a module over \( \mathbb{Z} \)
Vector spaces as modules over fields
Polynomial modules
Ideals as modules over themselves
Comparison to Vector Spaces
Ring vs Field as Scalar Set
Basis Concepts
Existence of basis
Dependence on ring properties (free vs non-free modules)
Dimension Differences
Vector space dimension is fixed
Module "rank" concept for free modules
Submodules and Direct Sums
Definition of Submodules
Closure under addition
Closure under scalar multiplication
Properties of Submodules
Inclusion relationships
Examples involving specific modules
Direct Sum of Modules
Construction of direct sums
Applications and examples
Internal vs External direct sums
Module Homomorphisms
Definition and Properties
Linear maps in the context of modules
Preservation of module structure
Kernel and Image
Definitions analogously to vector spaces
Relation to submodules
Module Isomorphisms
Definition and examples
Criteria for isomorphism
Relationship to vector spaces
Free Modules
Definition and Characteristics
Modules with a basis
Connection to free abelian groups
Basis and Dimension Theory
Existence of bases
Generating sets and relations
Construction and Examples
Direct product construction
\( R^n \) as a free module over a ring \( R \)
Special Cases and Non-examples
Non-free modules over non-principal ideal domains
Noetherian and Artinian Modules
Noetherian Modules
Definition: ascending chain condition
Examples and properties
Importance in algebraic geometry
Artinian Modules
Definition: descending chain condition
Examples in linear algebra
Connection to rings and field extensions
Relationship Between Noetherian and Artinian
Conditions for being both
Implications of the chain conditions
Applications in Theorems
Hilbert's Basis Theorem
Structure theorems for finitely generated modules
4. Fields
First Page
6. Advanced Topics