Results 11 to 20 of about 34 (34)
The pseudodifferential operator A(x, D)
International Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 8, Page 407-419, 2004., 2004 The pseudodifferential operator (p.d.o.) A(x, D), associated with the Bessel operator d2/dx2 + (1 − 4μ2)/4x2, is defined. Symbol class Hρ,δm is introduced. It is shown that the p.d.o. associated with a symbol belonging to this class is a continuous linear mapping of the Zemanian space Hμ into itself. An integral representation of p.d.o.
R. S. Pathak, S. Pathak
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International Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 53, Page 2821-2834, 2004., 2004 We extend the Putnam‐Fuglede theorem and the second‐degree Putnam‐Fuglede theorem to the nonnormal operators and to an elementary operator under perturbation by quasinilpotents. Some asymptotic results are also given.
Yin Chen
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Ill‐posed equations with transformed argument
Abstract and Applied Analysis, Volume 2003, Issue 13, Page 785-791, 2003., 2003 We discuss the operator transforming the argument of a function in the L2‐setting. Here this operator is unbounded and closed. For the approximate solution of ill‐posed equations with closed operators, we present a new view on the Tikhonov regularization.
Simone Gramsch, Eberhard Schock
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A note on best approximation and invertibility of operators on uniformly convex Banach spaces
International Journal of Mathematics and Mathematical Sciences, Volume 14, Issue 3, Page 611-614, 1991., 1991 It is shown that if X is a uniformly convex Banach space and S a bounded linear operator on X for which ‖I − S‖ = 1, then S is invertible if and only if . From this it follows that if S is invertible on X then either (i) dist(I, [S]) < 1, or (ii) 0 is the unique best approximation to I from [S], a natural (partial) converse to the well‐known sufficient
James R. Holub
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Joint numerical ranges: recent advances and applications minicourse by V. Müller and Yu. Tomilov
Concrete Operators, 2020 We present a survey of some recent results concerning joint numerical ranges of n-tuples of Hilbert space operators, accompanied with several new observations and remarks.
Müller V., Tomilov Yu.
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General numerical radius inequalities for matrices of operators
Open Mathematics, 2016 Let Ai ∈ B(H), (i = 1, 2, ..., n), and T=[0⋯0A1⋮⋰A200⋰⋰⋮An0⋯0] $ T = \left[ {\matrix{ 0 & \cdots & 0 & {A_1 } \cr \vdots & {\mathinner{\mkern2mu\raise1pt\hbox{.}\mkern2mu \raise4pt\hbox{.}\mkern2mu\raise7pt\hbox{.}\mkern1mu}} & {A_2 } & 0
Al-Dolat Mohammed +3 more
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A new view of some operators and their properties in terms of the Non-Newtonian Calculus
Topological Algebra and its Applications, 2017 Differentiation and integration are basic operations of calculus and analysis. Indeed, they are in- finitesimal versions of substraction and addition operations on numbers, respectively.
Ünlüyol Erdal +2 more
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Elliptic operators and their symbols
Demonstratio Mathematica, 2019 We consider special elliptic operators in functional spaces on manifolds with a boundary which has some singular points. Such an operator can be represented by a sum of operators, and for a Fredholm property of an initial operator one needs a Fredholm ...
Vasilyev Vladimir
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Product and factorization of hypo-EP operators
Special Matrices, 2018 In this article, we derive some necessary and sufficient conditions for the product of hypo-EP operators to be hypo-EP and we characterize hypo-EP operators through factorizations.
Johnson P. Sam, Vinoth A.
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A new extended Mulholland's inequality involving one partial sum
Open MathematicsBy using the weight coefficients and the techniques of real analysis, a new extended Mulholland’s inequality with multi-parameters involving one partial sum is given. The equivalent statements of the best value related to several parameters are provided.
Peng Ling, Yang Bicheng
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