Results 81 to 90 of about 1,122 (122)
, 2017 The well-known Hutchinson’s theorem states that if P be a polynomial with positive coefficients, P(x) = ∑k=0 akx k , and ak−1 ak−2ak 4 for k = 2,3, . . . ,n , then all the zeros of P are real. We obtain sufficient conditions for a real polynomial to be a
I. Karpenko, A. Vishnyakova
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B-statistical A-summability in conservative approximation
, 2016 This paper deals with the approximation of functions by sequences of linear operators via B -statistical A -summability. Quantitative results and asymptotic formulae are stated under a conservative approximation setting.
D. Cárdenas-Morales, P. Garrancho
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Essential norm of the weighted differentiation composition operator between Bloch-type spaces
Mathematical Inequalities & Applications, 2019 We give some characterizations for the boundedness and compactness of weighted differentiation composition operator Dφ,u between different Bloch spaces, and also estimate the essential norms of the operator, complementing some recent results in the ...
Cui Chen, Yu-Xia Liang
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Embeddings of rearrangement invariant spaces that are not strictly singular
, 1999 We give partial answers to the following conjecture: the natural embedding of a rearrangement invariant space E into L_1([0,1]) is strictly singular if and only if G does not embed into E continuously, where G is the closure of the simple functions in ...
Montgomery-Smith, S. J., Semenov, E. M.
core +1 more source
On the eleventh question of Allen Shields
Fixed Point Theory and Applications, 2011 In this article, we will give sufficient conditions for the boundedness of the analytic projection on the set of multipliers of the formal Laurent series spaces. This answers a question that has been raised by A. L. Shields.
Kashkooly Ali, Yousefi Bahmann
doaj
Full range boundedness of bilinear Hilbert transform along certain polynomials
Mathematical Inequalities & Applications, 2019 Let P and Q be two polynomials without constant term. Assume that the operator BP,Q( f ,g)(x) = ∫ f (x−P(t))g(x−Q(t)) dt t is bounded from Lp1 × Lp2 into Lr , p1, p2 ∈ (1,∞), 1 p1 + 1 p2 = r . It is proved that if P ′(t) > 0 for all t = 0 , then r d d+1 .
D. Dong
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Estimates of essential norm of the Li-Stević integral type operator between Zygmund type spaces
, 2016 For an analytic selfmap φ of the open unit disc D and an analytic function g on D , the Li-Stević integral type operator C φ is given by ( C φ f ) (z) = ∫ z 0 f ′(φ(ξ ))g(ξ )dξ .
A. Sanatpour
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Limiting ultrasymmetric sequence spaces
, 2016 The paper gives an analytic characterization of a class of ultrasymmetric sequence spaces that are very close to ∞ . We introduce discrete descriptions of limiting J and K interpolation methods, and we apply the results and the techniques developed to ...
P. Fernández-Martínez, T. Signes
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Operators commuting with complex symmetric weighted composition operators on H 2
Concrete OperatorsIn this article, we initially study when an anti-linear Toeplitz operator is in the commutant of a composition operator. Primarily, we investigate weighted composition operators Wg,ψ{W}_{g,\psi } commuting with complex symmetric weighted composition ...
Bhuia Sudip Ranjan
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Multiplication operators on the space of functions of bounded variation
Demonstratio Mathematica, 2017 In this paper,we study the properties of the multiplication operator acting on the bounded variation space BV[0, 1]. In particular,we show the existence of non-null compact multiplication operators on BV[0, 1] and non-invertible Fredholm multiplication ...
Astudillo-Villalba Franklin R. +1 more
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