Numerical Range

In the mathematical field of linear algebra and convex analysis, the numerical range or field of values of a complex n × n matrix A is the set

where x* denotes the Hermitian adjoint of the vector x.

In engineering, numerical ranges are used as a rough estimate of eigenvalues of A. Recently, generalizations of numerical range are used to study quantum computing.

A related concept is the numerical radius, which is the largest absolute values of the numbers in the numerical range, i.e.

r(A) is a norm.

Read more about Numerical Range:  Properties, Generalisations, See Also

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