Results 41 to 50 of about 2,695 (277)
The LQ/KYP problem for infinite-dimensional systems [PDF]
Opuscula Mathematica, 2017 Our aim is to present a solution to a general linear-quadratic (LQ) problem as well as to a Kalman-Yacubovich-Popov (KYP) problem for infinite-dimensional systems with bounded operators.
Piotr Grabowski
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Bounded Solutions of Semi-Linear Parabolic Differential Equations with Unbounded Delay Terms
Mathematics, 2023 In the present work, an initial boundary value problem (IBVP) for the semi-linear delay differential equation in a Banach space with unbounded positive operators is studied.
Allaberen Ashyralyev +1 more
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Lower bounds for unbounded operators and semigroups
Journal of Operator Theory, 2017 Let $A$ be an unbounded operator on a Banach space $X$. It is sometimes useful to improve the operator $A$ by extending it to an operator $B$ on a larger Banach space $Y$ with smaller spectrum. It would be preferable to do this with some estimates for the resolvent of $B$, and also to extend bounded operators related to $A$, for example a semigroup ...
Batty, C, Geyer, F
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Order compact and unbounded order compact operators
, 2021 We investigate properties of order compact, unbounded order compact and relatively uniformly compact operators acting on vector lattices. An operator is said to be order compact if it maps an arbitrary order bounded net to a net with an order convergent ...
Gezer, Niyazi Anıl +4 more
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Spectral order for unbounded operators [PDF]
, 2012 The spectral order, a notion originated by Olson for bounded operators, is investigated here in the context of unbounded operators. Dissimilarities between bounded and unbounded cases are pointed out.
Stochel, Jan, Płaneta, Artur
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Right (Or Left) Invertibility of Bounded and Unbounded Operators and Applications to the Spectrum of Products [PDF]
Complex Analysis and Operator Theory, 2017 09 ...
Dehimi, Souheyb, Mortad, Mohammed Hichem
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A new class of linear operators on ℓ2 and Schur multipliers for them
Journal of Function Spaces and Applications, 2007 We introduce the space Bw(ℓ2) of linear (unbounded) operators on ℓ2 which map decreasing sequences from ℓ2 into sequences from ℓ2 and we find some classes of operators belonging either to Bw(ℓ2) or to the space of all Schur multipliers on Bw(ℓ2).
Anca-Nicoleta Marcoci +1 more
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On Bounded Part of an Algebra of Unbounded Operators
Publications of the Research Institute for Mathematical Sciences, 1988 The author has characterized the symmetry of an \(Op^*\)-algebra \({\mathcal A}\) by topological properties of the bounded part \({\mathcal A}_ b\) of \({\mathcal A}:\) Theorem 1. (a) If \({\mathcal A}\) is symmetric, then \({\mathcal A}_ b\) is sequentially dense in any *-algebra topology \(\tau\) in \({\mathcal A}\) such that \(B_ 0\equiv \{T\in ...
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Advances in Difference Equations, 2021 In this paper, we prove two results concerning the existence of S-asymptotically ω-periodic solutions for non-instantaneous impulsive semilinear differential inclusions of order 1 < α < 2 ...
Zainab Alsheekhhussain +2 more
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Stability Conditions for Perturbed Semigroups on a Hilbert Space via Commutators
Communications in Advanced Mathematical Sciences, 2019 Let $A$ and $B$ be linear operators on a Hilbert space. Let $A$ and $A+B$ generate $C_0$-semigroups $e^{tA}$ and $e^{t(A+B)}$, respectively, and $e^{tA}$ be exponentially stable.
Michael Gil'
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