(quantum mechanics) The study of the analytic properties of scattering as a function of angular momentum, where the angular momentum is not restricted to an integer but may take any complex value.

Sigmund Freud's hypothesis, in the mid-1890s, that a repressed memory of an early childhood sexual abuse experience was the essential precondition for hysterical or obsessional symptoms.

The hypothesis that people perceive spoken words by identifying the vocal tract gestures with which they are pronounced rather than by identifying the sound patterns generated by speech.

(mathematics) Those theories extending the eigenvalue and eigenvector theory of a single square matrix to a much broader theory of the structure of operators in a variety of mathematical spaces.

(mathematics) A theory for atomic decomposition of a range of Banach spaces of distributions, including among others the wavelet transform and the short-time Fourier transform.

A mathematical formalism developed in the 1980s for the representation of meaning or semantics.

A mathematical formalism for describing knowledge of the world in terms of patterns that can be studied using statistical methods.

(physics) A type of field theory in which the Lagrangian is invariant under a continuous group of local transformations.

A postmodern approach to analysing intersubjective discourses, based on the ways that authority is rooted in individuals' knowledge and perspectives, and the power that such authority exerts.

(mathematics, algebra) A branch of mathematics that studies abstract algebraic structures by representing their elements as linear transformations of vector spaces, and studies modules over these abstract algebraic structures.