The theory (coherent scientific explanation of an observable fact) that some diseases are caused by microorganisms.

The theory of the psychological process whereby deliberate attempts to suppress certain thoughts make them more likely to surface.

(particle physics) A proposal for the resolution of the strong CP problem. It proposes that the QCD Lagrangian be extended with a CP-violating term known as the θ parameter, and that this should be a dynamic field rather than a constant value. It also predicts the existence of particles called axions.

A theory of cognition according to which visual and verbal information are both used to represent information, but processed in different ways.

A speculative theory of the origins of spoken language, according to which all things have a vibrating natural resonance, echoed somehow in the earliest words of human beings.

(mathematics, number theory) The branch of number theory in which number-theoretic questions are expressed in terms of properties of algebraic number fields or related objects, and studied using techniques from algebra.

plural of string theory

plural of quantum theory

plural of gauge theory

plural of percolation theory