On bases and unconditional bases in the spaces ,1≤p<∞
K. Kazarian (1982)
Studia Mathematica
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K. Kazarian (1982)
Studia Mathematica
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Robert E. Zink (2002)
Colloquium Mathematicae
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In one of the earliest monographs that involve the notion of a Schauder basis, Franklin showed that the Gram-Schmidt orthonormalization of a certain Schauder basis for the Banach space of functions continuous on [0,1] is again a Schauder basis for that space. Subsequently, Ciesielski observed that the Gram-Schmidt orthonormalization of any Schauder system is a Schauder basis not only for C[0,1], but also for each of the spaces , 1 ≤ p < ∞. Although perhaps not probable, the latter...
M. S. Moslehian, F. Mirzapour, A. Morassaei (2013)
Colloquium Mathematicae
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We investigate a notion of relative operator entropy, which develops the theory started by J. I. Fujii and E. Kamei [Math. Japonica 34 (1989), 341-348]. For two finite sequences A = (A₁,...,Aₙ) and B = (B₁,...,Bₙ) of positive operators acting on a Hilbert space, a real number q and an operator monotone function f we extend the concept of entropy by setting , and then give upper and lower bounds for as an extension of an inequality due to T. Furuta [Linear Algebra Appl. 381 (2004),...
Iwona Piotrowska (2008)
Banach Center Publications
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The present paper is devoted to the study of the “quality” of the compactness of the trace operator. More precisely, we characterize the asymptotic behaviour of entropy numbers of the compact map , where Γ is a d-set with 0 < d < n and a weight of type near Γ with ϰ > -(n-d). There are parallel results for approximation numbers.
Bernd Carl, David E. Edmunds (2003)
Studia Mathematica
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For a precompact subset K of a Hilbert space we prove the following inequalities: , n ∈ ℕ, and , k,n ∈ ℕ, where cₙ(cov(K)) is the nth Gelfand number of the absolutely convex hull of K and and denote the kth entropy and kth dyadic entropy number of K, respectively. The inequalities are, essentially, a reformulation of the corresponding inequalities given in [CKP] which yield asymptotically optimal estimates of the Gelfand numbers cₙ(cov(K)) provided that the entropy numbers εₙ(K)...
Tomek Bartoszyński, Mirna Džamonja, Lorenz Halbeisen, Eva Murtinová, Anatolij Plichko (2005)
Studia Mathematica
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We investigate various kinds of bases in infinite-dimensional Banach spaces. In particular, we consider the complexity of Hamel bases in separable and non-separable Banach spaces and show that in a separable Banach space a Hamel basis cannot be analytic, whereas there are non-separable Hilbert spaces which have a discrete and closed Hamel basis. Further we investigate the existence of certain complete minimal systems in as well as in separable Banach spaces.
Robert E. Zink (1989)
Colloquium Mathematicae
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Jorge Mujica, Daniela M. Vieira (2010)
Studia Mathematica
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Let E be a separable Banach space with the λ-bounded approximation property. We show that for each ϵ > 0 there is a Banach space F with a Schauder basis such that E is isometrically isomorphic to a 1-complemented subspace of F and, moreover, the sequence (Tₙ) of canonical projections in F has the properties and . This is a sharp quantitative version of a classical result obtained independently by Pełczyński and by Johnson, Rosenthal and Zippin.
David Burguet (2015)
Fundamenta Mathematicae
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We study the jumps of topological entropy for interval or circle maps. We prove in particular that the topological entropy is continuous at any with . To this end we study the continuity of the entropy of the Buzzi-Hofbauer diagrams associated to interval maps.
Dmitry Gavinsky, Pavel Pudlák (2016)
Commentationes Mathematicae Universitatis Carolinae
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How low can the joint entropy of -wise independent (for ) discrete random variables be, subject to given constraints on the individual distributions (say, no value may be taken by a variable with probability greater than , for )? This question has been posed and partially answered in a recent work of Babai [Entropy versus pairwise independence (preliminary version), http://people.cs.uchicago.edu/ laci/papers/13augEntropy.pdf, 2013]. In this paper we improve some...
Alexander P. Stone (1966)
Annales de l'institut Fourier
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Soient un anneau de germes de fonctions analytiques, le -module de formes différentielles à coefficients dans , et un endomorphisme de . On veut trouver les formes exactes telles que le soit aussi. On suppose deux conditions supplémentaires vérifiées : les valeurs propres de sont distinctes dans , et la torsion de Nijenhuis s’annule. Dans ces conditions il y a une décomposition de en somme directe, étant engendré par les formes propres dont les valeurs propres...
Mehdi Rahimi (2015)
Kybernetika
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In this paper, a local approach to the concept of -entropy is presented. Applying the Choquet‘s representation Theorem, the introduced concept is stated in terms of -entropy.
S. J. Dilworth, M. Soto-Bajo, V. N. Temlyakov (2012)
Studia Mathematica
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We study Lebesgue-type inequalities for greedy approximation with respect to quasi-greedy bases. We mostly concentrate on the spaces. The novelty of the paper is in obtaining better Lebesgue-type inequalities under extra assumptions on a quasi-greedy basis than known Lebesgue-type inequalities for quasi-greedy bases. We consider uniformly bounded quasi-greedy bases of , 1 < p < ∞, and prove that for such bases an extra multiplier in the Lebesgue-type inequality can be taken...
A. Kamont (1992)
Studia Mathematica
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The asymptotic behaviour of ε-entropy of classes of Lipschitz functions in is obtained. Moreover, the asymptotics of ε-entropy of classes of Lipschitz functions in whose tail function decreases as is obtained. In case p = 1 the relation between the ε-entropy of a given class of probability densities on and the minimax risk for that class is discussed.
Michael Langenbruch (2012)
Annales Polonici Mathematici
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We prove precise decomposition results and logarithmically convex estimates in certain weighted spaces of holomorphic germs near ℝ. These imply that the spaces have a basis and are tamely isomorphic to the dual of a power series space of finite type which can be calculated in many situations. Our results apply to the Gelfand-Shilov spaces and for α > 0 and to the spaces of Fourier hyperfunctions and of modified Fourier hyperfunctions.