In theoretical physics, a dynamical horizon (DH) is a local description (i.e. independent of the global structure of space–time) of evolving black-hole horizons. In the literature there exist two different mathematical formulations of DHs—the 2+2 formulation developed first by Sean Hayward and the 3+1 formulation developed by Abhay Ashtekar and others (see ). It provides a description of a black hole that is evolving (e.g. one that has a non-zero mass–energy influx). A related formalism, for black holes with zero influx, is an isolated horizon.
Formal definition.
The formal definition of a dynamical horizon is as follows:
 ;templatestyles src="Template:Blockquote/styles.css" / ;A smooth, three-dimensional, space-like submanifold (possibly with boundary) Σ of space–time M is said to be a dynamical horizon if it can be foliated by a family of closed 2-manifolds such that on each leaf "L"
References.
Cross-reference.
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Sources used.
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