Below you see the MCS codes list with links to the forums already created. To require the creation of a new forum, please contact helpdesk@mathdir.org.

**MSC codes (first level)**

**General and Foundations**

**00**: General

(including recreational mathematics, philosophy of mathematics and mathematical modeling.)

**01**: History and biography

**03**: Mathematical logic and foundations

(including model theory, computability theory, set theory, proof theory, and algebraic logic)

**Discrete Mathematics and Algebra**

**05**: Combinatorics

**06**: Order theory

**08**: General algebraic systems

**11**: Number theory

**12**: Field theory and polynomials

**13**: Commutative rings and algebras

**14**: Algebraic geometry

**15**: Linear and multilinear algebra; matrix theory

**16**: Associative rings and associative algebras

**17**: Non-associative rings and non-associative algebras

**18**: Category theory; homological algebra

**19**: K-theory

**20**: Group theory and generalizations

**22**: Topological groups, Lie groups, and analysis upon them

**Analysis**

**26**: Real functions, including derivatives and integrals

**28**: Measure and integration

**30**: Complex functions, including approximation theory in the complex domain

**31**: Potential theory

**32**: Several complex variables and analytic spaces

**33**: Special functions

**34**: Ordinary differential equations

**35**: Partial differential equations

**37**: Dynamical systems and ergodic theory

**39**: Difference equations and functional equations

**40**: Sequences, series, summability

**41**: Approximations and expansions

**42**: Harmonic analysis

(including Fourier analysis, Fourier transforms, trigonometric approximation, trigonometric interpolation, and orthogonal functions)

**43**: Abstract harmonic analysis

**44**: Integral transforms, operational calculus

**45**: Integral equations

**46**: Functional analysis

(including infinite-dimensional holomorphy, integral transforms in distribution spaces)

**47**: Operator theory

**49**: Calculus of variations and optimal control; optimization

**Geometry and Topology**

**51**: Geometry

**52**: Convex geometry and discrete geometry

**53**: Differential geometry

**54**: General topology

**55**: Algebraic topology

**57**: Manifolds

**58**: Global analysis, analysis on manifolds

(including infinite-dimensional holomorphy)

**Applied Mathematics and Other**

**60**Probability theory, stochastic processes

**62**Statistics

**65**Numerical analysis

**68**Computer science

**70**Mechanics

(including particle mechanics)

**74**Mechanics of deformable solids

**76**Fluid mechanics

**78**Optics, electromagnetic theory

**80**Classical thermodynamics, heat transfer

**81**Quantum theory

**82**Statistical mechanics, structure of matter

**83**Relativity and gravitational theory

(including relativistic mechanics)

**85**Astronomy and astrophysics

**86**Geophysics

**90**Operations research, mathematical programming

**91**Game theory, economics, social and behavioral sciences

**92**Biology and other natural sciences

**93**Systems theory; control

(including optimal control)

**94**Information and communication, circuits

**97**Mathematics education