Results 81 to 90 of about 1,463 (129)
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2014 In this paper, using the boundary properties of the analytic functions we investigate the structure of the discrete spectrum of the boundary value problem (0.1)iy1'+q1(x)y2−λy1=ϕ1(x) −iy2'+q2(x)y1−λy2=ϕ2(x),x∈R+$$\matrix{\hfill {iy_1^\prime + q_1 \left ...
Karaman Özkan
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Weyl's theorem and its perturbations for the functions of operators
, 2018 In this paper, we study the stability of Weyl’s theorem under compact perturbations, and characterize those operators satisfying that the stability of Weyl’s theorem does not hold for any integer powers of the operator. Mathematics subject classification
X. Cao, Jiong Dong, Jun Liu
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A note on preservers of pseudo spectrum of matrix products
Operators and Matrices, 2019 Let M2 be the algebra of 2×2 complex matrices. For ε > 0 , complete descriptions are given of the maps of M2 leaving invariant the ε -pseudo spectrum of A ∗B , where A ∗B stands either for the Jordan semi-triple product ABA or the skew product AB∗ on ...
M. Bendaoud, A. Benyouness, M. Sarih
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Semigroup estimates and fast-slow dynamics in parabolic-hyperbolic systems
Advances in Nonlinear Analysis, 2018 We present a general procedure to describe slow dynamics in parabolic-hyperbolic systems, under suitable assumptions on the terms appearing in the equations. In particular, our strategy relies in semigroup estimates for the evolution system associated to
Strani Marta
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On quasi-∗-n-paranormal operators
, 2015 For a positive integer n , an operator T ∈ B(H) is called quasi-∗ -n -paranormal if ||T 2+nx|| 1 1+n ||Tx|| n 1+n ||T ∗Tx|| for every x∈H , which is a further generalization of hyponormal and a subclass of normaloid.
Fei Zuo
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Maps preserving the peripheral local spectrum of some product of operators
Operators and Matrices, 2019 Let H and K be two infinite-dimensional complex Hilbert spaces. Let B(H ) denote the algebra of all bounded linear operators on H . If T is an operator in B(H ) and x a vector in H then γT (x) denotes the peripheral local spectrum of T at x .
A. E. Ghazi, Rabi Marzouki
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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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Spectrum of the quadratic eigenparameter dependent discrete Dirac equations
, 2014 Let us consider the Boundary Value Problem (BVP) for the discrete Dirac equations an+1yn+1(2)+bnyn(2)+pnyn(1)=λyn(1), an−1yn−1(1)+bnyn(1)+qnyn(2)=λyn(2), n∈N, (γ0+γ1λ+γ2λ2)y1(2)+(β0+β1λ+β2λ2)y0(1)=0, where (an), (bn), (pn) and (qn), n∈N are complex ...
T. Koprubasi
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Boundary Value Problems, 2011 The purpose of writing this article is to show some spectral properties of the Bessel operator equation, with spectral parameter-dependent boundary condition.
Aslanova Nigar
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On a nonlocal problem for fractional differential equations via resolvent operators
, 2014 Using the techniques of approximate solutions, the analytic resolvent method, and the uniform continuity of the resolvent, we discuss the existence of mild solutions for nonlocal fractional differential equations governed by a linear closed operator ...
Lizhen Chen, Z. Fan, Gang Li
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