Results 1 to 10 of about 596 (38)
Global Perturbation of Nonlinear Eigenvalues
Advanced Nonlinear Studies, 2021 This paper generalizes the classical theory of perturbation of eigenvalues up to cover the most general setting where the operator surface 𝔏:[a,b]×[c,d]→Φ0(U,V){\mathfrak{L}:[a,b]\times[c,d]\to\Phi_{0}(U,V)}, (λ,μ)↦𝔏(λ,μ){(\lambda,\mu)\mapsto\mathfrak ...
López-Gómez Julián +1 more
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Generalized lower characteristic involving measures of non-strict singularity
Topological Algebra and its Applications, 2023 This work establishes a connection between the class of generalized lower characteristic operators and [⋅]a{\left[\cdot ]}_{a} acting on a Banach space involving measures of non-strict singularity.
Baraket Sami +2 more
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On (m, P)-expansive operators: products, perturbation by nilpotents, Drazin invertibility
Concrete Operators, 2021 A generalisation of m-expansive Hilbert space operators T ∈ B(ℋ) [18, 20] to Banach space operators T ∈ B(𝒳) is obtained by defining that a pair of operators A, B ∈ B(𝒳) is (m, P)-expansive for some operator P ∈ B(𝒳) if Δ A,Bm(P)= (I-LARB)m(P)=∑j=0m(-1)j(
Duggal B.P.
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Structure of n-quasi left m-invertible and related classes of operators
Demonstratio Mathematica, 2020 Given Hilbert space operators T,S∈B(ℋ)T,S\in B( {\mathcal H} ), let Δ\text{Δ} and δ∈B(B(ℋ))\delta \in B(B( {\mathcal H} )) denote the elementary operators ΔT,S(X)=(LTRS−I)(X)=TXS−X{\text{Δ}}_{T,S}(X)=({L}_{T}{R}_{S}-I)(X)=TXS-X and δT,S(X)=(
Duggal Bhagwati Prashad, Kim In Hyun
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PT Symmetric Schr\"odinger Operators: Reality of the Perturbed Eigenvalues [PDF]
, 2010 We prove the reality of the perturbed eigenvalues of some PT symmetric Hamiltonians of physical interest by means of stability methods. In particular we study 2-dimensional generalized harmonic oscillators with polynomial perturbation and the one ...
Caliceti, Emanuela +2 more
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Perturbation of eigenvalues of matrix pencils and optimal assignment problem [PDF]
, 2004 We consider a matrix pencil whose coefficients depend on a positive parameter $\epsilon$, and have asymptotic equivalents of the form $a\epsilon^A$ when $\epsilon$ goes to zero, where the leading coefficient $a$ is complex, and the leading exponent $A ...
Baccelli +13 more
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Spectrum perturbations of compact operators in a Banach space
Open Mathematics, 2019 For an integer p ≥ 1, let Γp be an approximative quasi-normed ideal of compact operators in a Banach space with a quasi-norm NΓp(.) and the ...
Gil’ Michael
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On a problem in eigenvalue perturbation theory [PDF]
, 2015 We consider additive perturbations of the type $K_t=K_0+tW$, $t\in [0,1]$, where $K_0$ and $W$ are self-adjoint operators in a separable Hilbert space $\mathcal{H}$ and $W$ is bounded.
Gesztesy, Fritz +2 more
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Finite rank perturbations and solutions to the operator Riccati equation [PDF]
, 2015 We consider an off-diagonal self-adjoint finite rank perturbation of a self-adjoint operator in a complex separable Hilbert space $\mathfrak{H}_0 \oplus \mathfrak{H}_1$, where $\mathfrak{H}_1$ is finite dimensional.
Großmann, Julian P.
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Many parameter Hoelder perturbation of unbounded operators
, 2009 If $u\mapsto A(u)$ is a $C^{0,\alpha}$-mapping, for $0< \alpha \le 1$, having as values unbounded self-adjoint operators with compact resolvents and common domain of definition, parametrized by $u$ in an (even infinite dimensional) space, then any ...
A. Frölicher +10 more
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