Results 241 to 250 of about 2,288,250 (268)
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Polarization Constant for the Numerical Radius
Mediterranean Journal of Mathematics, 2020Given a symmetric \(m\)-linear mapping \(A:X\times\dots\times X \to Y\) (\(X,Y\) are Banach spaces) and its associated \(m\)-homogeneous polynomial \(\widehat A: X\to Y\), the following polarization inequalities hold: \[\|\hat{A}\| \le \|A\| \le \frac{m^m}{m!} \|\hat{A}\|.\] For specific Banach spaces, the second inequality holds with constants \(C ...
Javier Falcó +4 more
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Linear and Multilinear Algebra, 2002
Let V be a direct sum of full matrix algebras, or the algebra of block upper triangular matrices. Suppose r ( A ) is the numerical radius of $A \in V$ . We characterize mappings $f: V \rightarrow V$ that satisfy $r(\;f(A)-f(B)) = r(A-B) \ {\rm for \ all} \ A, B \in V$ .
Peter Šemrl, Chi-Kwong Li
exaly +2 more sources
Let V be a direct sum of full matrix algebras, or the algebra of block upper triangular matrices. Suppose r ( A ) is the numerical radius of $A \in V$ . We characterize mappings $f: V \rightarrow V$ that satisfy $r(\;f(A)-f(B)) = r(A-B) \ {\rm for \ all} \ A, B \in V$ .
Peter Šemrl, Chi-Kwong Li
exaly +2 more sources
Numerical radius and unitarity
Acta Scientiarum Mathematicarum, 2010Takashi Sano, Atsushi Uchiyama
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Numerical-Radius-Attaining Polynomials
The Quarterly Journal of Mathematics, 2003zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Acosta, M. D. +2 more
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Algorithms for the computation of the pseudospectral radius and the numerical radius of a matrix
IMA Journal of Numerical Analysis, 2005This paper concerns the convergence of a discrete-time dynamical system \[ x_k= Ax_{k-1},\quad A\in \mathbb{C}^{n\times n}.\tag{1} \] For \(k\to\infty\), the eigenvalues of the matrix \(A\) provide all information for analyzing (1), as is known.
Mengi, Emre, Overton, Michael L.
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Berezin Number and Numerical Radius Inequalities
Vietnam Journal of Mathematics, 2023zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Anirban Sen, Kallol Paul
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Numerical radius of a multigraph
Ars Comb., 1996zbMATH Open Web Interface contents unavailable due to conflicting licenses.
I. Andrew Affleck, Douglas R. Farenick
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A generalization of the numerical radius
Linear Algebra and its Applications, 2019zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Abu-Omar, Amer, Kittaneh, Fuad
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Geometric computation of the numerical radius of a matrix
Numerical Algorithms, 2009zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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Inequalities for Numerical Radius and Spectral Radius
Journal of Advanced Mathematics and Applications, 2016M. Al-Hawari, Sa'ed M. Barahmeh
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