Results 31 to 40 of about 288 (48)

Patterns with several multiple eigenvalues

Special Matrices, 2014
Identified are certain special periodic diagonal matrices that have a predictable number of pairedeigenvalues. Since certain symmetric Toeplitz matrices are special cases, those that have several multiple 5eigenvalues are also investigated further.
Dorsey J., Johnson C.R., Wei Z.
doaj   +1 more source

Arov--Krein entropy functionals and indefinite interpolation problems

, 2019
We generalize the notion of the Arov-Krein entropy functional for the case of generalized Nevanlinna functions and obtain a representation of these functionals on solutions of indefinite interpolation problems. The case of indefinite Caratheodory problem
Roitberg, I., Sakhnovich, A. L.
core   +1 more source

Explicit determinants, inverses and eigenvalues of four band Toeplitz matrices with perturbed rows

Special Matrices, 2019
In this paper, four-band Toeplitz matrices and four-band Hankel matrices of type I and type II with perturbed rows are introduced. Explicit determinants, inverses and eigenvalues for these matrices are derived by using a nice inverse formula of block ...
Zhang Maoyun, Jiang Xiaoyu, Jiang Zhaolin   +2 more
doaj   +1 more source

Eigenvalues of even very nice Toeplitz matrices can be unexpectedly erratic

, 2017
It was shown in a series of recent publications that the eigenvalues of $n\times n$ Toeplitz matrices generated by so-called simple-loop symbols admit certain regular asymptotic expansions into negative powers of $n+1$. On the other hand, recently two of
Barrera, Mauricio, Boettcher, Albrecht, Grudsky, Sergei M., Maximenko, Egor A.   +3 more
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Tunable localisation in parity-time-symmetric resonator arrays with imaginary gauge potentials

Forum of Mathematics, Sigma
The aim of this paper is to illustrate both analytically and numerically the interplay of two fundamentally distinct non-Hermitian mechanisms in the deep subwavelength regime.
Habib Ammari, Silvio Barandun, Ping Liu, Alexander Uhlmann   +3 more
doaj   +1 more source

Representation of Cyclotomic Fields and Their Subfields [PDF]

, 2012
Let $\K$ be a finite extension of a characteristic zero field $\F$. We say that the pair of $n\times n$ matrices $(A,B)$ over $\F$ represents $\K$ if $\K \cong \F[A]/$ where $\F[A]$ denotes the smallest subalgebra of $M_n(\F)$ containing $A$ and $$ is an
A. K. Lal, A. Satyanarayana, K Mehta, Reddy Shashank   +3 more
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Spectral behavior of preconditioned non-Hermitian multilevel block Toeplitz matrices with matrix-valued symbol

, 2014
This note is devoted to preconditioning strategies for non-Hermitian multilevel block Toeplitz linear systems associated with a multivariate Lebesgue integrable matrix-valued symbol.
Donatelli, Marco, Garoni, Carlo, Mazza, Mariarosa, Serra-Capizzano, Stefano, Sesana, Debora   +4 more
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Explicit inverse of symmetric, tridiagonal near Toeplitz matrices with strictly diagonally dominant Toeplitz part

Special Matrices
Let Tn=tridiag(−1,b,−1){T}_{n}={\rm{tridiag}}\left(-1,b,-1), an n×nn\times n symmetric, strictly diagonally dominant tridiagonal matrix (∣b∣>2| b| \gt 2). This article investigates tridiagonal near-Toeplitz matrices T˜n≔[t˜i,j]{\widetilde{T}}_{n}:= \left[
Kurmanbek Bakytzhan, Erlangga Yogi, Amanbek Yerlan   +2 more
doaj   +1 more source

Four-dimensional Riemannian product manifolds with circulant structures

, 2019
A 4-dimensional Riemannian manifold equipped with an additional tensor structure, whose fourth power is the identity, is considered. This structure has a circulant matrix with respect to some basis, i.e.
Dokuzova, Iva
core  

Multitaper estimation on arbitrary domains

, 2020
Multitaper estimators have enjoyed significant success in estimating spectral densities from finite samples using as tapers Slepian functions defined on the acquisition domain.
Andén, Joakim, Romero, José Luis
core