Current sheetA current sheet is an electric current that is confined to a surface, rather than being spread through a volume of space. Current sheets feature in magnetohydrodynamics (MHD), the study of the behavior of electrically conductive fluids: if there is an electric current through part of the volume of such a fluid, magnetic forces tend to expel it from the fluid, compressing the current into thin layers that pass through the volume.
Causal structureIn mathematical physics, the causal structure of a Lorentzian manifold describes the causal relationships between points in the manifold. In modern physics (especially general relativity) spacetime is represented by a Lorentzian manifold. The causal relations between points in the manifold are interpreted as describing which events in spacetime can influence which other events. The causal structure of an arbitrary (possibly curved) Lorentzian manifold is made more complicated by the presence of curvature.
Lange modelThe Lange model (or Lange–Lerner theorem) is a neoclassical economic model for a hypothetical socialist economy based on public ownership of the means of production and a trial-and-error approach to determining output targets and achieving economic equilibrium and Pareto efficiency. In this model, the state owns non-labor factors of production, and markets allocate final goods and consumer goods.
Globally hyperbolic manifoldIn mathematical physics, global hyperbolicity is a certain condition on the causal structure of a spacetime manifold (that is, a Lorentzian manifold). It's called hyperbolic because the fundamental condition that generates the Lorentzian manifold is (t and r being the usual variables of time and radius) which is one of the usual equations representing an hyperbola. But this expression is only true relative to the ordinary origin; this article then outline bases for generalizing the concept to any pair of points in spacetime.
Austrian school of economicsThe Austrian School is a heterodox school of economic thought that advocates strict adherence to methodological individualism, the concept that social phenomena result exclusively from the motivations and actions of individuals. Austrian school theorists hold that economic theory should be exclusively derived from basic principles of human action. The Austrian School originated in Vienna with the work of Carl Menger, Eugen von Böhm-Bawerk, Friedrich von Wieser, and others.
Causality (physics)Physical causality is a physical relationship between causes and effects. It is considered to be fundamental to all natural sciences and behavioural sciences, especially physics. Causality is also a topic studied from the perspectives of philosophy, statistics and logic. Causality means that an effect can not occur from a cause that is not in the back (past) light cone of that event. Similarly, a cause can not have an effect outside its front (future) light cone.
