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Showing 1 to 8 of 8 for “"Compact Operator"”.
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On the Numerical Range of Compact Operators
<p>One of the many characterizations of compact operators is as linear operators which<br />can be closely approximated by bounded finite rank operators (theorem 25). It is<br />well known that the numerical range of a bounded operator on a finite dimensional<br />Hilbert space is closed (theorem …
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Invariant Subspace Problem and Spectral Properties of Bounded Linear Operators on Banach Spaces, Banach Lattices, and Topological Vector Spaces
… if S and T are two commuting positive continuous operators with finite spectral radii on a locally convex-solid vector lattice, T is locally quasinilpotent at a positive vector, and S dominates a positive compact operator, then S and T have a common closed non-trivial invariant subspace.
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On Symmetric Operator Ideals and s-Numbers
… between various <em>s</em>-numbers of an operator<em> T</em> and its adjoint <em>T</em>∗ between Banach spaces. For non-compact operator <em>T</em> ∈ <em>L</em>(<em>X, Y</em> ), we do not have a lot of information about the relationship between n-th <em>s</em>-number, …
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REGULARIZATION METHODS FOR ILL-POSED POISSON IMAGING
… to have the form z = Au, where A is a linear, compact operator, the problem of minimizing the negative log-Poisson likelihood function is ill-posed, and hence some form of regularization is required. In this work, it involves solving a variational problem of the form u def = arg min u0 `(Au; z) …
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REGULARIZATION METHODS FOR ILL-POSED POISSON IMAGING
… to have the form z = Au, where A is a linear, compact operator, the problem of minimizing the negative log-Poisson likelihood function is ill-posed, and hence some form of regularization is required. In this work, it involves solving a variational problem of the form u def = arg min u0 `(Au; z) …
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Boundary value and Wiener-Hopf problems for abstract kinetic equations with nonregular collision operators
… a Hilbert space H, T is a self adjoint injective operator on H and A is an accretive operator. The first step in the analysis of this boundary value problem is to show that T⁻¹A generates a holomorphic bisemigroup. We prove two theorems about perturbation of bisemigroups that are interesting in …
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Digital Curvature Estimation: An Operator Theoretic Approach
… and introduce the Bernstein and the Schoenberg operator on the space of continuous functions and its generalization to the Lp-spaces. In order to be able to detect C2-singularities in piecewise smooth curves, we establish lower estimates for the approximation error in terms of the second order …
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Ideals and Commutators of Operators
<p>Subideals. A subideal of operators is an ideal of J (called a J-ideal) for J an arbitraryideal of B(H). Necessary and sufficient conditions are determined for a finitely generatedsubideal to be also an ideal of B(H) and then these conditions are exploited to characterizeall finitely generated …