Results 31 to 40 of about 94 (89)
Extending partial isometries [PDF]
Israel Journal of Mathematics, 2005 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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Function theory, geometry, and circular numerical ranges
Concrete OperatorsWe introduce the reader to partial isometries and their properties. In particular, we consider the Gau-Wang-Wu conjecture from 2016: When is the numerical range of a partial isometry circular?
Adams Gregory, Gorkin Pamela
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On Extensions of Partial Isometries
In this paper we define a notion of S-extension for a metric space and study minimality and coherence of S-extensions. We show that every S-extension can be identified with an algebraic object. We use this algebraic representation to give a complete characterization of all finite minimal S-extensions of a given finite metric space and a complete ...
Mahmood Etedadialiabadi, Su Gao
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Approximation by partial isometries [PDF]
Proceedings of the Edinburgh Mathematical Society, 1986 Let B(H) be the algebra of bounded linear operators on a complex separable Hilbert space H. The problem of operator approximation is to determine how closely each operator T ∈B(H) can be approximated in the norm by operators in a subset L of B(H). This problem is initiated by P. R.
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, 2018 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Fernández-Polo, Francisco J +1 more
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A combinatorial proof of the extension property for partial isometries [PDF]
Commentationes Mathematicae Universitatis Carolinae, 2019 We present a short and self-contained proof of the extension property for partial isometries of the class of all finite metric spaces.
Jan Hubicka +2 more
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On low-dimensional partial isometries
The Electronic Journal of Linear Algebra, 2023 Two statements concerning $n$-by-$n$ partial isometries are being considered: (i) these matrices are generic, if unitarily irreducible, and (ii) if nilpotent, their numerical ranges are circular disks. Both statements hold for $n\leq 4$ but fail starting with $n=5$.
Qixiao He +2 more
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Orbit Representations from Linear mod 1 Transformations
Symmetry, Integrability and Geometry: Methods and Applications, 2012 We show that every point $x_0in [0,1]$ carries a representationof a $C^*$-algebra that encodes the orbit structure of thelinear mod 1 interval map $f_{eta,alpha}(x)=eta x +alpha$.
Carlos Correia Ramos +2 more
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N=4 Multi-Particle Mechanics, WDVV Equation and Roots
Symmetry, Integrability and Geometry: Methods and Applications, 2011 We review the relation of N=4 superconformal multi-particle models on the real line to the WDVV equation and an associated linear equation for two prepotentials, F and U.
Olaf Lechtenfeld +2 more
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Which Operators are Similar to Partial Isometries? [PDF]
Proceedings of the American Mathematical Society, 1976 Let H \mathcal {H} denote a separable, infinite dimensional complex
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