کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4624087 1339532 2006 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Extremal non-compactness of composition operators with linear fractional symbol
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات آنالیز ریاضی
پیش نمایش صفحه اول مقاله
Extremal non-compactness of composition operators with linear fractional symbol
چکیده انگلیسی

We realize the norms of certain composition operators Cφ with linear fractional symbol acting on the Hardy space in terms of the roots of associated hypergeometric functions. This realization leads to simple necessary and sufficient conditions on φ for Cφ to exhibit extremal non-compactness, establishes equivalence of cohyponormality and cosubnormality of composition operators with linear fractional symbol, and yields a complete classification of those linear fractional φ that induce composition operators whose norms are determined by the action of the adjoint on the normalized reproducing kernels in H2.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Mathematical Analysis and Applications - Volume 322, Issue 2, 15 October 2006, Pages 749-763