Let be a unital -algebra, then an element is called an isometry if .
Isometry Element
This entry contributed by Mohammad Sal Moslehian
Explore with Wolfram|Alpha
References
Murphy, G. J. C-*-Algebras and Operator Theory. New York: Academic Press, 1990.Referenced on Wolfram|Alpha
Isometry ElementCite this as:
Moslehian, Mohammad Sal. "Isometry Element." From MathWorld--A Wolfram Web Resource, created by Eric W. Weisstein. https://mathworld.wolfram.com/IsometryElement.html