Bands, Riesz subspaces and projections
نویسندگان
چکیده
منابع مشابه
Weighted projections and Riesz frames
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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Linear combinations of exponentials e iλ k t in the case where the distance between some points λ k tends to zero are studied. D. Ull-rich [30] has proved the basis property of the divided differences of exponentials in the case when {λ k } = Λ (n) and the groups Λ (n) consist of equal number of points all of them are close enough to n, n ∈ Z. We have generalized this result for groups with arb...
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In this article we suppose that E is an ordered Banach space the positive cone of which is defined by a countable familyF={fi|i ∈ N} of positive continuous linear functionals of E, i.e. E+ = {x ∈ E | fi(x) ≥ 0, for each i} and we study the existence of positive (Schauder) bases in the ordered subspaces X of E with the Riesz decomposition property. So we consider the elements x of E as sequences...
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ژورنال
عنوان ژورنال: Indagationes Mathematicae (Proceedings)
سال: 1982
ISSN: 1385-7258
DOI: 10.1016/s1385-7258(82)80011-5