کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4615137 1339308 2015 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
AOP mappings and the distance to the scalar multiples of isometries
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات آنالیز ریاضی
پیش نمایش صفحه اول مقاله
AOP mappings and the distance to the scalar multiples of isometries
چکیده انگلیسی

In this paper, linear ε  -orthogonality preserving mappings are studied. We define εˆ(T) as the smallest ε for which T is ε  -orthogonality preserving, and then derive an exact formula for εˆ(T) in terms of ‖T‖‖T‖ and the minimum modulus m(T)m(T) of T. We see that ε  -orthogonality preserving mappings (for some ε<1ε<1) are exactly the operators that are bounded from below. We improve an upper bound in the stability equation given in [7, Theorem 2.3], which was thought to be sharp.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Mathematical Analysis and Applications - Volume 431, Issue 2, 15 November 2015, Pages 1275–1284
نویسندگان
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