plural of quantum field theory

plural of grand unification theory

(sociology) Any of various models of group behavior (such as economic behavior, criminal behavior, or consumer behavior) as the cumulative result of rational choices made by individuals expressing on their preferences and/or meeting their needs.

Used other than figuratively or idiomatically: see group, theory; a theory about (particular kinds of) groups.

(chemistry) Any theory that relates collisions among particles to reaction rate; reaction rate depends on such factors as concentration, surface area, temperature, stirring, and the presence of either a catalyst or an inhibitor.

(mathematics) The study of differentiable functions, where the domain of each is a manifold and the codomain is the real line.

(biology) A theory of evolution, especially the scientific theory of evolution through natural selection. / (by extension) Any model of disequilibrium or accumulating change.

An interdisciplinary field of science which studies the nature of complex systems in nature, society and science, and studies complex parts of reality as systems.

A political theory that holds that control of Eurasia and Africa (the World Island) is achieved via control of the countries bordering the Soviet Union

(physics) A theory developed in the early 20th century, according to which nuclear and radiation phenomena can be explained by assuming that energy only occurs in discrete amounts called quanta.