Invariant

From Wikipedia, the free encyclopedia

Invariant may have several meanings, among which are:

• Invariant (computer science), an expression whose value doesn't change during program execution
• In computer science, a type in overriding that is neither covariant nor contravariant
• Invariant (mathematics), something unaltered by a transformation, for example: taking a homotopy group functor on the category of topological spaces. Then, homomeomorphic spaces have isomorphic fundamental group. See topological invariant.
• Invariant (music)
• Invariant (physics), meaning that something does not change under a transformation, such as from one reference frame to another
• Writer invariant, property of a text which is similar in all texts of a given author, and different in texts of different authors.
• Invariant Point (physics), A unique condition of temperature, pressure and concentration in a system, which allows a number of phases to coexist in equilibrium.
• Invariant representation (cognitive science), the form or essence of something, an abstraction from particulars
• The Invariant Society, the undergraduate mathematical society of Oxford University