(psychology) An early hypothesis as to the origin and nature of emotions, stating that physiological arousal instigates the experience of emotion.

A theoretical explanation for departures from ideality in solutions of electrolytes.

(criminology) A criminological theory stating that signs of urban decay (e.g. broken windows, graffiti) signal that an area is not monitored, encouraging more destructive criminal behavior.

Information theory adapted to deal with information held and/or handled by quantum systems, i.e., in which information is measured in qubits instead of classical bits.

(physics, chemistry) A method of determining the structure of a molecule by assuming that electrons are not fixed to bonds between individual atoms

(Christianity, theology, informal) The Christus Victor theory of atonement.

(mathematics)

(creationism) A neo-creationist hypothesis which claims that the first life and the universe appeared abruptly, and that plants and animals appeared abruptly in complex form.

(history, linguistics, Indo-European studies) The hypothesis that the Aryans are indigenous to the Indian subcontinent, and that the Indo-European languages radiated out from a homeland in India into their present locations.

(uncountable, mathematics, graph theory) The subbranch of graph theory in which algebraic methods are applied to problems about graphs.