(number theory) A set of general techniques for computing or estimating the size of sifted sets of integers.

(economics) an economic theory that attempts to explain the exchange value or price of goods and services

(economics) The economy theory based around the cobweb model.

(mathematics) A theory of integral equations, concerning itself in the narrowest sense with the solution of the Fredholm integral equation.

A branch of probability theory that generalizes the compound Poisson process for arbitrary holding times.

A scientific theory that has been disproved, or for which attempts to prove it have failed, but which continues to be presented as a viable theory.

(medicine, historical) An obsolete theory of disease, proposing that a weak body attracts germs.

(mathematics) The systematic study of the situation of maps' having a homotopy between them; the study of equivalence classes (called homotopy classes) of maps.

(complex analysis) A part of the theory of meromorphic functions that describes the asymptotic distribution of solutions to the equation ƒ(z) = a, as a varies.

(complex analysis, differential geometry) A geometric counterpart to Nevanlinna theory that extends the applicability of the concept of covering surface (of a topological space) by defining a covering number (a generalised "degree of covering") applicable to any bordered Riemann surface equipped with a conformal Riemannian metric.