Results 1 to 10 of about 1,249,970 (217)

Quaternionic numerical range of complex matrices [PDF]

, 2023
This paper explores further the computation of the quaternionic numerical range of a complex matrix. We prove a modified version of a conjecture by So and Thompson.
Diogo, C., Mendes, S., Carvalho, L.
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Norm and Numerical Radius Inequalities for a Product of Two Linear Operators in Hilbert Spaces [PDF]

, 2006
The main aim of the present paper is to establish some norm and numerical radius inequalities for the composite operator BA under suitable assumptions for the transform Cα ,β (T) := (T∗ −α I)(β I−T) , where α ,β ∈ C and T ∈ B(H), of the operators ...
S. S. Dragomir, Dragomir, Sever S, Sever Silvestru Dragomir   +2 more
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The block numerical range of analytic operator functions [PDF]

, 2014
We introduce the block numerical range Wn(L) of an operator function L with respect to a decomposition H = H1⊕. . .⊕Hn of the underlying Hilbert space.
Markus Wagenhofer, Christiane Tretter, Radl, Agnes, Wagenhofer, Markus, Agnes Radl, Tretter, Christiane   +5 more
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From the Kirsch-Kress potential method via the range test to the singular sources method

, 2022
We review three reconstruction methods for inverse obstacle scattering problems. We will analyse the relation between the Kirsch-Kress potential method 1986, the range test of Kusiak, Potthast and Sylvester (2003) and the singular sources method of ...
Schulz, J., J Schulz, ; 1Institute for Numerical and Applied Mathematics, University of Göttingen, Germany, Potthast, R., R Potthast, ; 1Institute for Numerical and Applied Mathematics, University of Göttingen, Germany   +3 more
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More on geometry of Krein space C-numerical range [PDF]

, 2019
For n × n complex matrices A, C and H, where H is non-singular Hermitian, the Krein space C-numerical range of A induced by H is the subset of the complex plane given by {Tr(CU^[*]AU: U^{-1}= U^[*] )} with U^[*]=H^{-1}U*H the H-adjoint matrix of U.
Lemos, Rute, Soares, Graça, Guterman, Alexander   +2 more
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Perron-Frobenius type results on the numerical range

, 2002
We present results connecting the shape of the numerical range to intrinsic properties of a matrix A. When A is a nonnegative matrix, these results are to a large extent analogous to the Perron–Frobenius theory, especially as it pertains to ...
Maroulas, J., Psarrakos, P.J., Maroulas, J, Tsatsomeros, MJ, Psarrakos, PJ, Tsatsomeros, M.J.   +5 more
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A new method for the determination of the locking range of oscillators [PDF]

, 2007
A time-domain method for the determination of the injection-locking range of oscillators is presented. The method involves three time dimensions: the first and the second are warped time scales used for the free-running frequency and the external ...
Condon, Marissa, Xu, Tao, Carlos E. Christoffersen, Marissa Condon, Christoffersen, Carlos E., Tao Xu   +5 more
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The C-Numerical Range in Infinite Dimensions

, 2018
In infinite dimensions and on the level of trace-class operators $C$ rather than matrices, we show that the closure of the $C$-numerical range $W_C(T)$ is always star-shaped with respect to the set $\operatorname{tr}(C)W_e(T)$, where $W_e(T)$ denotes the
Ende, Frederik vom, Dirr, Gunther
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The c-numerical range of tridiagonal matrices

, 2001
We give sufficient conditions for the c-numerical range of a tridiagonal matrix to be an elliptic disc, which generalize known results on the classical numerical ...
Mao-Ting Chien, Nakazato, Hiroshi, Chien, Mao-Ting, Hiroshi Nakazato   +3 more
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Some Inequalities of the Gruss Type for the Numerical Radius of Bounded Linear Operators in Hilbert Spaces [PDF]

, 2008
Some inequalities of the Gr¨ uss type for the numerical radius of bounded linear operators in Hilbert spaces are ...
S. S. Dragomir, Dragomir, Sever S, Dragomir SS   +2 more
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