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Basic language

Algebraic structures are defined primarily as sets with operations.

  • Algebraic structure
  • Subobjects: subgroup, subring, subalgebra, submodule etc.
  • Binary operation
  • Closure of an operation
  • Associative property
  • Distributive property
  • Commutative property
  • Unary operator
  • Additive inverse, multiplicative inverse, inverse element
  • Identity element
  • Cancellation property
  • Finitary operation
  • Arity

Structure preserving maps called homomorphisms are vital in the study of algebraic objects.

  • Homomorphisms
  • Kernels and cokernels
  • Image and coimage
  • Epimorphisms and monomorphisms
  • Isomorphisms
  • Isomorphism theorems

There are several basic ways to combine algebraic objects of the same type to produce a third object of the same type. These constructions are used throughout algebra.

  • Direct sum
  • Direct limit
  • Direct product
  • Inverse limit
  • Quotient objects: quotient group, quotient ring, quotient module etc.
  • Tensor product

Advanced concepts:

  • Category theory
  • Category of groups
  • Category of abelian groups
  • Category of rings
  • Category of modules (over a fixed ring)
  • Morita equivalence, Morita duality
  • Category of vector spaces
  • Homological algebra
  • Filtration (algebra)
  • Exact sequence
  • Functor
  • Zorn's lemma

Semigroups and monoids

  • Semigroup
  • Subsemigroup
  • Free semigroup
  • Green's relations
  • Inverse semigroup (or inversion semigroup, cf. [https://www.encyclopediaofmath.org/index.php/Inversion_semi-group])
  • Krohn–Rhodes theory
  • Semigroup algebra
  • Transformation semigroup
  • Monoid
  • Aperiodic monoid
  • Free monoid
  • Monoid (category theory)
  • Monoid factorisation
  • Syntactic monoid

Group theory

Structure

  • Group (mathematics)
  • Lagrange's theorem (group theory)
  • Subgroup
  • Coset
  • Normal subgroup
  • Characteristic subgroup
  • Centralizer and normalizer subgroups
  • Derived group
  • Frattini subgroup
  • Fitting subgroup
  • Classification of finite simple groups
  • Sylow theorems
  • Local analysis

Constructions

  • Free group
  • Presentation of a group
  • Word problem for groups
  • Quotient group
  • Extension problem
  • Direct sum, direct product
  • Semidirect product
  • Wreath product

Types

  • Simple group
  • Finite group
  • Abelian group
  • Torsion subgroup
  • Free abelian group
  • Finitely generated abelian group
  • Rank of an abelian group
  • Cyclic group
  • Locally cyclic group
  • Solvable group
  • Composition series
  • Nilpotent group
  • Divisible group
  • Dedekind group, Hamiltonian group

Examples

  • Examples of groups
  • Trivial group
  • Additive group
  • Permutation group
  • Symmetric group
  • Alternating group
  • p-group
  • List of small groups
  • Klein four-group
  • Quaternion group
  • Dihedral group
  • Dicyclic group
  • Automorphism group
  • Point group
  • Circle group
  • Linear group
  • Orthogonal group

Applications

  • Group action
  • Conjugacy class
  • Inner automorphism
  • Conjugate closure
  • Stabilizer subgroup
  • Orbit (group theory)
  • Orbit-stabilizer theorem
  • Cayley's theorem
  • Burnside's lemma
  • Burnside's problem
  • Loop group
  • Fundamental group

Ring theory

General

  • Ring (mathematics)
  • Commutative algebra, Commutative ring
  • Ring theory, Noncommutative ring
  • Algebra over a field
  • Non-associative algebra
  • Relatives to rings: Semiring, Nearring, Rig (algebra)

Structure

  • Subring, Subalgebra
  • Center (algebra)
  • Ring ideal
  • Principal ideal
  • Ideal quotient
  • Maximal ideal, minimal ideal
  • Primitive ideal, prime ideal, semiprime ideal
  • Radical of an ideal
  • Jacobson radical
  • Socle of a ring
  • unit (ring theory), Idempotent, Nilpotent, Zero divisor
  • Characteristic (algebra)
  • Ring homomorphism, Algebra homomorphism
  • Ring epimorphism
  • Ring monomorphism
  • Ring isomorphism
  • Skolem–Noether theorem
  • Graded algebra
  • Morita equivalence
  • Brauer group
  • Stable range condition

Constructions

  • Direct sum of rings, Product of rings
  • Quotient ring
  • Matrix ring
  • Endomorphism ring
  • Polynomial ring
  • Formal power series
  • Monoid ring, Group ring
  • Localization of a ring
  • Tensor algebra
  • Symmetric algebra, Exterior algebra, Clifford algebra
  • Free algebra
  • Completion (ring theory)

Types

  • Field (mathematics), Division ring, division algebra
  • Simple ring, Central simple algebra, Semisimple ring, Semisimple algebra
  • Primitive ring, Semiprimitive ring
  • Prime ring, Semiprime ring, Reduced ring
  • Integral domain, Domain (ring theory)
  • Field of fractions, Integral closure
  • Euclidean domain, Principal ideal domain, Unique factorization domain, Dedekind domain, Prüfer domain
  • Von Neumann regular ring
  • Quasi-Frobenius ring
  • Hereditary ring, Semihereditary ring
  • Local ring, Semi-local ring
  • Discrete valuation ring
  • Regular local ring
  • Cohen–Macaulay ring
  • Gorenstein ring
  • Artinian ring, Noetherian ring
  • Perfect ring, semiperfect ring
  • Baer ring, Rickart ring
  • Lie ring, Lie algebra
  • Ideal (Lie algebra)
  • Jordan algebra
  • Differential algebra
  • Banach algebra

Examples

  • Rational number, Real number, Complex number, Quaternions, Octonions
  • Hurwitz quaternion
  • Gaussian integer

Theorems and applications

  • Algebraic geometry
  • Hilbert's Nullstellensatz
  • Hilbert's basis theorem
  • Hopkins–Levitzki theorem
  • Krull's principal ideal theorem
  • Levitzky's theorem
  • Galois theory
  • Abel–Ruffini theorem
  • Wedderburn–Artin theorem
  • Jacobson density theorem
  • Wedderburn's little theorem
  • Lasker–Noether theorem

Field theory

Basic concepts

  • Field (mathematics)
  • Subfield (mathematics)
  • Multiplicative group
  • Primitive element (field theory)
  • Field extension
  • Algebraic extension
  • Splitting field
  • Algebraically closed field
  • Algebraic element
  • Algebraic closure
  • Separable extension
  • Separable polynomial
  • Normal extension
  • Galois extension
  • Abelian extension
  • Transcendence degree
  • Field norm
  • Field trace
  • Conjugate element (field theory)
  • Tensor product of fields

Types

  • Algebraic number field
  • Global field
  • Local field
  • Finite field
  • Symmetric function
  • Formally real field
  • Real closed field

Applications

  • Galois theory
  • Galois group
  • Inverse Galois problem
  • Kummer theory

Module theory

General

  • Module (mathematics)
  • Bimodule
  • Annihilator (ring theory)

Structure

  • Submodule
  • Pure submodule
  • Module homomorphism
  • Essential submodule
  • Superfluous submodule
  • Singular submodule
  • Socle of a module
  • Radical of a module

Constructions

  • Free module
  • Quotient module
  • Direct sum, Direct product of modules
  • Direct limit, Inverse limit
  • Localization of a module
  • Completion (ring theory)

Types

  • Simple module, Semisimple module
  • Indecomposable module
  • Artinian module, Noetherian module
  • Homological types:
  • Projective module
  • Projective cover
  • Swan's theorem
  • Quillen–Suslin theorem
  • Injective module
  • Injective hull
  • Flat module
  • Flat cover
  • Coherent module
  • Finitely-generated module
  • Finitely-presented module
  • Finitely related module
  • Algebraically compact module
  • Reflexive module

Concepts and theorems

  • Composition series
  • Length of a module
  • Structure theorem for finitely generated modules over a principal ideal domain
  • Homological dimension
  • Projective dimension
  • Injective dimension
  • Flat dimension
  • Global dimension
  • Weak global dimension
  • Cohomological dimension
  • Krull dimension
  • Regular sequence (algebra), depth (algebra)
  • Fitting lemma
  • Schur's lemma
  • Nakayama's lemma
  • Krull–Schmidt theorem
  • Steinitz exchange lemma
  • Jordan–Hölder theorem
  • Artin–Rees lemma
  • Schanuel's lemma
  • Morita equivalence
  • Progenerator

Representation theory

Representation theory (& outline)

  • Algebra representation
  • Group representation
  • Lie algebra representation
  • Maschke's theorem
  • Schur's lemma
  • Equivariant map
  • Frobenius reciprocity
  • Induced representation
  • Restricted representation
  • Affine representation
  • Projective representation
  • Modular representation theory
  • Quiver (mathematics)
  • Representation theory of Hopf algebras

Non-associative systems

General

  • Associative property, Associator
  • Heap (mathematics)
  • Magma (algebra)
  • Loop (algebra), Quasigroup
  • Nonassociative ring, Non-associative algebra
  • Universal enveloping algebra
  • Lie algebra (see also list of Lie group topics and list of representation theory topics)
  • Jordan algebra
  • Alternative algebra
  • Power associativity
  • Flexible algebra

Examples

  • Cayley–Dickson construction
  • Octonions
  • Sedenions
  • Trigintaduonions
  • Hyperbolic quaternions
  • Virasoro algebra

Generalities

  • Algebraic structure
  • Universal algebra
  • Variety (universal algebra)
  • Congruence relation
  • Free object
  • Generating set (universal algebra)
  • Clone (algebra)
  • Kernel of a function
  • Kernel (algebra)
  • Isomorphism class
  • Isomorphism theorem
  • Fundamental theorem on homomorphisms
  • Universal property
  • Filtration (mathematics)
  • Category theory
  • Monoidal category
  • Groupoid
  • Group object
  • Coalgebra
  • Bialgebra
  • Hopf algebra
  • Magma object
  • Torsion (algebra)

Computer algebra

  • Symbolic mathematics
  • Finite field arithmetic
  • Gröbner basis
  • Buchberger's algorithm

See also

  • List of commutative algebra topics
  • List of homological algebra topics
  • List of linear algebra topics
  • List of algebraic structures
  • Glossary of field theory
  • Glossary of group theory
  • Glossary of ring theory
  • Glossary of tensor theory