Angle criteria for frame sequences and frames containing a Riesz basis
نویسندگان
چکیده
منابع مشابه
tight frame approximation for multi-frames and super-frames
در این پایان نامه یک مولد برای چند قاب یا ابر قاب تولید شده تحت عمل نمایش یکانی تصویر برای گروه های شمارش پذیر گسسته بررسی خواهد شد. مثال هایی از این قاب ها چند قاب های گابور، ابرقاب های گابور و قاب هایی برای زیرفضاهای انتقال پایاست. نشان می دهیم که مولد چند قاب تنک نرمال شده (ابرقاب) یکتا وجود دارد به طوری که مینیمم فاصله را از ان دارد. همچنین مسایل مشابه برای قاب های دوگان مطرح شده و برخی ...
15 صفحه اولFrames containing a Riesz basis and preservation of this property under perturbations
Aldroubi has shown how one can construct any frame {gi}i=1 starting with one frame {fi}i=1,using a bounded operator U on l2(N). We study the overcompleteness of the frames in terms of properties of U . We also discuss perturbation of frames in the sense that two frames are “close” if a certain operator is compact. In this way we obtain an equivalence relation with the property that members of t...
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The Feichtinger Conjecture, if true, would have as a corollary that for each set E ⊂ T and Λ ⊂ Z, there is a partition Λ1, . . . ,ΛN of Z such that for each 1 ≤ i ≤ N , {exp(2πixλ) : λ ∈ Λi} is a Riesz sequence. In this paper, sufficient conditions on sets E ⊂ T and Λ ⊂ R are given so that {exp(2πixλ)1E : λ ∈ Λ} can be uniformly partitioned into Riesz sequences.
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Let H be a (separable) Hilbert space and {ek}k≥1 a fixed orthonormal basis of H. Motivated by many papers on scaled projections, angles of subspaces and oblique projections, we define and study the notion of compatibility between a subspace and the abelian algebra of diagonal operators in the given basis. This is used to refine previous work on scaled projections, and to obtain a new characteri...
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ژورنال
عنوان ژورنال: Journal of Mathematical Analysis and Applications
سال: 2008
ISSN: 0022-247X
DOI: 10.1016/j.jmaa.2008.05.095