On mappings approximately preserving orthogonality

[摘要] We answer a question posed by Chmielinski, whether a linear map which approximately preserves orthogonality must be close to an orthogonality preserving one. Furthermore, we give a short proof of the stability of the orthogonality equation on finite dimensional Hilbert spaces. (c) 2007 Elsevier Inc. All rights reserved.

[发布日期] 2007-12-01

[关键词] approximate orthogonality;orthogonality equation;orthogonality preserving mapping;stability