Star domain

In mathematics we mean by a star-shaped lot of a subset of to which there is a point ( a star center and a star center ), from which all points of the set are "visible", that is, any straight line segment connecting any a point lies entirely in.

Is a star-shaped lot in addition open, then one speaks of a star field.

Formal definition

A set is star-shaped if there is a such that, for all the distance

Is a subset of.

Comments

• Each non-empty convex set is star-shaped.
• The set of possible rating centers is also the center of the set. It can be shown that it is always convex. A lot of true if and only consistent with its center when it is convex.
• Star-shaped sets are contractible.
• Star quantities are arcwise connected.
• A star field is a field.