Results 11 to 20 of about 173,772,216 (255)
Effective perturbation theory for linear operators
Journal of Operator Theory, 2017 We propose a new approach to the spectral theory of perturbed linear operators , in the case of a simple isolated eigenvalue. We obtain two kind of results: ''radius bounds'' which ensure perturbation theory applies for perturbations up to an explicit size, and ''regularity bounds'' which control the variations of eigendata to any order.
Kloeckner, Benoît
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Open Mathematics, 2021 This work intends to treat the existence of mild solutions for the Hilfer fractional hybrid differential equation (HFHDE) with linear perturbation of first and second type in partially ordered Banach spaces. First, we establish the results concerning the
Gabeleh Moosa +3 more
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The technique of splitting operators in perturbation control theory [PDF]
, 2005 summary:The paper presents the technique of splitting operators, intended for perturbation analysis of control problems involving unitary matrices. Combined with the technique of Lyapunov majorants and the application of the Banach or Schauder fixed ...
Christov, Nicolai D. +2 more
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Unbounded B-Fredholm operators on Hilbert spaces [PDF]
, 2008 This paper is concerned with the study of a class of closed linear operators densely defined on a Hilbert space H and called B-Fredholm operators.
Berkani, M. +3 more
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Nuclear Physics B, 2018 We continue our study of string theory in a background that interpolates between AdS3 in the infrared and a linear dilaton spacetime R1,1×Rϕ in the UV.
Meseret Asrat +3 more
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Parity and generalized multiplicity [PDF]
, 1991 Assuming that X and Y are Banach spaces and that T is a path of linear Fredholm operators with invertible endpoints, in [F-Pl] we defined a homotopy invariant "the parity of T .
Fitzpatrickp. +4 more
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Divergences in open quantum systems
Journal of High Energy Physics, 2018 We show that for cubic scalar field theories in five and more spacetime dimensions, and for the T = 0 limit of the Caldeira-Leggett model, the quantum master equation for long-wavelength modes initially unentangled from short-distance modes, and at ...
Cesar Agón, Albion Lawrence
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Comments on the quantum field theory of the Coulomb gas formalism
Journal of High Energy Physics, 2021 The holomorphic Coulomb gas formalism, as developed by Feigin-Fuchs, Dotsenko-Fateev and Felder, is a set of rules for computing minimal model observables using free field techniques. We attempt to derive and clarify these rules using standard techniques
Daniel Kapec, Raghu Mahajan
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Applications of cosmological perturbation theory [PDF]
, 2011 PhDCosmological perturbation theory is crucial for our understanding of the universe. The linear theory has been well understood for some time, however developing and applying the theory beyond linear order is currently at the forefront of research in
Christopherson, Adam J.
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Perturbation of normal quaternionic operators [PDF]
, 2019 The theory of quaternionic operators has applications in several different fields, such as quantum mechanics, fractional evolution problems, and quaternionic Schur analysis, just to name a few.
Sabadini I. +3 more
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