Results 31 to 40 of about 579 (72)
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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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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Orbits of Linear Operators Tending to Infinity
, 2009 Let T be a bounded linear operator on a (real or complex) Banach space X satisfying ∑∞ n=1 1 ‖T n‖ < ∞. Then there is a unit vector x ∈ X such that ‖Tnx‖ → ∞. If X is a complex Hilbert space then it is sufficient to assume that ∑∞ n=1 1 ‖T n‖ < ∞.
V. Müller, Jan Vrs˘ovský
semanticscholar +1 more source
A distance formula related to a family of projections orthogonal to their symmetries
, 2017 Let u be a hermitian involution, and e an orthogonal projection, acting on the same Hilbert space. We establish the exact formula, in terms of the norm of eue, for the distance from e to the set of all orthogonal projections q from the algebra generated ...
Spitkovsky, Ilya M.
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One-sided star partial orders for bounded linear operators
, 2015 We compare some recent approaches to transferring the notions of leftand rightstar partial order, introduced for complex matrices in early 90-ies, to bounded linear Hilbert space operators, and discuss a new version of these orders.
J. Cı̄rulis
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Closable Hankel operators and moment problems
, 2019 In a paper from 2016 D. R. Yafaev considers Hankel operators associated with Hamburger moment sequences q_n and claims that the corresponding Hankel form is closable if and only if the moment sequence tends to 0.
Berg, Christian, Szwarc, Ryszard
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Some spectral properties of fourth order differential operator equation
, 2018 We consider boundary value problem for fourth order differential equation with unbounded discrete operator coefficient. One of the boundary conditions involves the λ parameter. The asymptotics of spectrum of corresponding selfadjoint operator is obtained.
N. Aslanova +2 more
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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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The existence and expressions of the inverse along operators B and C
, 2018 For given A,B,C ∈B(H ) , if there exists X ∈B(H ) such that XAB = B , CAX =C , R(X) = R(B) and R(X∗) = R(C∗), then A is called (B,C) -invertible and X is called the (B,C) -inverse of A .
Chunyan Deng, Rufang Liu
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Distance estimates, norm of Hankel operators and related questions
, 2018 We consider Berezin symbols and Hankel operators on the Hardy space H2(D) over the unit disc D = {z ∈ C : |z| < 1} and give their some applications. Namely, we estimate in terms of Hankel operators and Berezin symbols the distances from a given operator ...
N. Altwaijry, A. Baazeem, M. Garayev
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