Mathematics Branches, Topics, and Sub-Topics

A structured visual guide to the major mathematical areas and their relationships.

Search by code, branch, topic, subtopic, or a keyword from the descriptions.

51Axx Linear incidence geometry

This subtopic introduces the core ideas in linear incidence geometry, including foundational concepts, standard methods, and the main questions used to organize the area. Typical uses include building mathematical background, framing related research problems, and supporting applications in neighboring fields where these concepts provide useful structure.

Specific topics

51A05 General theory and projective geometries

Overview

Projective geometry studies incidence and perspectivity properties that remain invariant under projective transformations.

Related Wikipedia Page

Wikipedia: Projective geometry

Useful Links

Key Ideas

  • projective spaces
  • cross-ratios
  • perspectivities

Typical Uses

Fundamental in computer vision, architecture, and classical geometry.

Applications

  • Computer graphics
  • Camera calibration
  • Synthetic geometry

References

Recommended Textbooks

51A10 Homomorphism, automorphism and dualities in linear incidence geometry

Overview

This topic studies maps between incidence structures that preserve geometric operations and the duality relations between them.

Related Wikipedia Page

Wikipedia: Incidence geometry

Useful Links

Key Ideas

  • automorphisms
  • duality
  • incidence-preserving maps

Typical Uses

Important for classifying geometric structures and understanding symmetry.

Applications

  • Finite geometries
  • Coding theory
  • Synthetic geometry

References

Recommended Textbooks

51A15 Structures with parallelism

Overview

Parallelism gives incidence structures an additional notion of direction and leads to affine and related geometries.

Related Wikipedia Page

Wikipedia: Affine geometry

Useful Links

Key Ideas

  • parallel classes
  • affine spaces
  • direction sets

Typical Uses

Central in elementary geometry and modern incidence theory.

Applications

  • Computer graphics
  • Affine spaces
  • Design theory

References

Recommended Textbooks

51A20 Configuration theorems in linear incidence geometry

Overview

Configuration theorems describe finite arrangements of points and lines whose incidence properties are constrained by geometric laws.

Related Wikipedia Page

Wikipedia: Configuration (geometry)

Useful Links

Key Ideas

  • Pappus
  • Desargues
  • incidence configurations

Typical Uses

Useful for proving structural properties of geometric systems.

Applications

  • Synthetic geometry
  • Combinatorics
  • Finite geometry

References

Recommended Textbooks

51A25 Algebraization in linear incidence geometry

Overview

Algebraization translates incidence geometry into algebraic structures such as vector spaces, fields, and division rings.

Related Wikipedia Page

Wikipedia: Projective space

Useful Links

Key Ideas

  • vector spaces
  • coordinate systems
  • algebraic models

Typical Uses

A bridge between synthetic geometry and algebra.

Applications

  • Coordinate geometry
  • Finite projective spaces
  • Coding theory

References

Recommended Textbooks

51A30 Desarguesian and Pappian geometries

Overview

These geometries satisfy the Desargues and Pappus theorems, giving especially rich algebraic structure and a direct connection to projective spaces over division rings or fields.

Related Wikipedia Page

Wikipedia: Projective geometry

Useful Links

Key Ideas

  • Desargues theorem
  • Pappus theorem
  • coordinate fields

Typical Uses

Central to the classification of projective spaces and incidence structures.

Applications

  • Foundations of geometry
  • Algebraic geometry
  • Finite geometry

References

Recommended Textbooks

51A35 Non-Desarguesian affine and projective planes

Overview

Non-Desarguesian planes are geometric structures that fail to satisfy the Desargues theorem and therefore cannot be coordinatized by a field in the usual way.

Related Wikipedia Page

Wikipedia: Projective plane

Useful Links

Key Ideas

  • translation planes
  • projective planes
  • exceptional geometries

Typical Uses

Important in finite geometry and combinatorial design.

Applications

  • Finite projective planes
  • Design theory
  • Coding theory

References

Recommended Textbooks

51A40 Translation planes and spreads in linear incidence geometry

Overview

Translation planes and spreads are geometric structures built from families of subspaces and are central to the study of finite and infinite projective planes.

Related Wikipedia Page

Wikipedia: Spread (finite geometry)

Useful Links

Key Ideas

  • spreads
  • translation planes
  • subspace partitions

Typical Uses

Used to construct and analyze special incidence geometries.

Applications

  • Finite geometry
  • Combinatorial design
  • Coding theory

References

Recommended Textbooks

51A45 Incidence structures imbeddable into projective geometries

Overview

This area studies incidence structures that can be represented as subsets or substructures of projective spaces.

Related Wikipedia Page

Wikipedia: Projective space

Useful Links

Key Ideas

  • embeddings
  • substructures
  • realizability

Typical Uses

Useful for determining when abstract incidence data is geometrically realizable.

Applications

  • Finite geometry
  • Combinatorics
  • Graph drawing

References

Recommended Textbooks

51A50 Polar geometry, symplectic spaces, orthogonal geometry

Overview

Polar geometry studies incidence relations defined by forms such as symplectic and orthogonal bilinear forms.

Related Wikipedia Page

Wikipedia: Polar space

Useful Links

Key Ideas

  • polar spaces
  • quadrics
  • symplectic forms

Typical Uses

Fundamental in finite geometry, Lie theory, and classical groups.

Applications

  • Classical groups
  • Finite geometry
  • Coding theory

References

Recommended Textbooks