Results 21 to 30 of about 60 (58)
Pairs of closed geodesics in metric graphs
Demonstratio MathematicaIn this paper we study the counting pairs of closed geodesics on metric graphs. We obtain an asymptotic for the number of pairs of closed geodesics ordered by their word lengths on the metric graph, such that the difference of their geometric lengths ...
Saif Al Abri Al Jalila
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Demonstratio MathematicaIf T1{{\mathbb{T}}}_{1} and T2{{\mathbb{T}}}_{2} are commuting dd-tuples of Hilbert space operators in B(ℋ)dB{\left({\mathcal{ {\mathcal H} }})}^{d} such that (T1*⊗I+I⊗T2*,T1⊗I+I⊗T2)\left({{\mathbb{T}}}_{1}^{* }\otimes I+I\otimes {{\mathbb{T}}}_{2}^{* },{
Duggal Bhagwati Prashad, Kim In Hyoun
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The basic propositions on defect numbers, root numbers and indices of linear operators [PDF]
, 2020 : In this work, we use the notion of the measure of noncompactness in order to establish some results concerning the class of semi-Fredholm and Fredholm operators.
Weidmann +13 more
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Operators with equal projections related to their generalized inverses [PDF]
, 2004 In this article we characterize operators on Banach spaces which have the same projections related to their outer or inner generalized inverses. As corollaries, we obatin well-known results for the Drazin inverse of bounded operators. Keywords: Outer and
Yimin Wei, Dragan S Djordjević
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Spectral points of type π+ and type π- of closed operators in indefinite inner product spaces [PDF]
, 2014 We introduce the notion of spectral points of type π+ and type π− of closed operators A in a Hilbert space which is equipped with an indefinite inner product. It is shown that these points are stable under compact perturbations.
Trunk, Carsten, Philipp, Friedrich
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Computation of Eigenvalues of Discrete Lower Semibounded Operators
, 2016 Based on the Galerkin method, the formulas for eigenvalues of discrete lower semibounded operators were obtained. Numerical experiments demonstrated high accuracy and computational efficiency of them.
Galiya A Zakirova, Sergey I Kadchenko
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Perturbation Bounds For Isotropic Invariant Subspaces Of Skew-Hamiltonian Matrices
, 2008 We investigate the behavior of isotropic invariant subspaces of skew-Hamiltonian matrices under structured perturbations. It is shown that finding a nearby subspace is equivalent to solving a certain quadratic matrix equation.
Daniel Kressner
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Expansion of eigenvalues of the perturbed discrete bilaplacian. [PDF]
Mon Hefte Math, 2022 Kholmatov SY +2 more
europepmc +1 more source
, 2001 Let (U(t))t≥0 be a C0-semigroup of bounded linear operators on a Banach space X. In this paper, we establish that if, for some t0> 0, U(t0) is a Fredholm (resp., semi-Fredholm) operator, then (U(t))t≥0 is a Fredholm (resp., semi-Fredholm) semi-group ...
Khalid Latrach, Abdelkader Dehici
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On the Properties for Iteration of a Compact Operator with Unstructured Perturbation
, 1996 . We consider certain speed estimates for Krylov subspace methods (such as GMRES) when applied upon systems consisting of a compact operator K with small unstructured perturbation B.
Jarmo Malinen
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