(logic) Recursion theory. / (computer science) The branch of the theory of computation that studies which problems are computationally solvable using different models.

The branch of abstract algebra dealing with group characters.

(mathematics) A branch of mathematics concerned with dynamical systems which suffer sudden qualitative changes from an infinitesimal change in a parameter.

(algebra, field theory) The branch of mathematics dealing with Galois groups, Galois fields, and polynomial equations.

(mathematics) The branch of mathematics dealing with the art of transmitting messages reliably over a noisy channel by adding redundancy to the message.

(mathematics) The branch of mathematics dealing with dynamical systems which can undergo abrupt irreversible qualitative changes due to a tiny change in parameters.

(mathematics) A branch of mathematics which deals with spaces and maps between them in abstraction, taking similar theorems from various disparate more concrete branches of mathematics and unifying them.

(physics) A candidate unified theory of all physical forces and particles; a theory which suggests that subatomic particles are one-dimensional strings rather than zero-dimensional points. It also suggests that space-time can have up to nine dimensions, plus the dimension of time.

The branch of mathematics dealing with the algebraic structure of rings.

A theory developed by Terence McKenna that aims to describe "novelty" in the universe based on a combination of numerology and mathematics, and supposed fractal patterns in the I Ching.