Journal of Inequalities and Applications
Volume 2006 (2006), Article ID 76489, 9 pages

Orthogonality preserving property, Wigner equation, and stability

Jacek Chmieliński

Instytut Matematyki, Akademia Pedagogiczna w Krakowie, Podchorążych 2, Kraków 30-084, Poland

Received 3 November 2005; Accepted 2 July 2006

Copyright © 2006 Jacek Chmieliński. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We deal with the stability of the orthogonality preserving property in the class of mappings phase-equivalent to linear or conjugate-linear ones. We give a characterization of approximately orthogonality preserving mappings in this class and we show some connections between the considered stability and the stability of the Wigner equation.