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Articles 1 - 30 of 94

Full-Text Articles in Physical Sciences and Mathematics

An Unnoticed Consequence Of Szego's Distribution Theorem, William F. Trench Nov 2014

An Unnoticed Consequence Of Szego's Distribution Theorem, William F. Trench

William F. Trench

No abstract provided.


Inverse Problems For Unilevel Block $\Alpha$-Circulants, William F. Trench Feb 2013

Inverse Problems For Unilevel Block $\Alpha$-Circulants, William F. Trench

William F. Trench

No abstract provided.


An Elementary View Of Weyl's Theory Of Equal Distribution, William Trench Jan 2012

An Elementary View Of Weyl's Theory Of Equal Distribution, William Trench

William F. Trench

No abstract provided.


Characterization And Properties Of $(R,S_\Sigma)$-Commutative Matrices, William F. Trench Dec 2011

Characterization And Properties Of $(R,S_\Sigma)$-Commutative Matrices, William F. Trench

William F. Trench

No abstract provided.


Characterization And Properties Of $(R,S_\Sigma)$-Commutative Matrices, William F. Trench Dec 2011

Characterization And Properties Of $(R,S_\Sigma)$-Commutative Matrices, William F. Trench

William F. Trench

Let $R=P \diag(\gamma_{0}I_{m_{0}}, \gamma_{1}I_{m_{1}}, \dots, \gamma_{k-1}I_{m_{k-1}})P^{-1}\in\mathbb{C}^{m\times m}$ and $S_{\sigma}=Q\diag(\gamma_{\sigma(0)}I_{n_{0}},\gamma_{\sigma(1)}I_{n_{1}}, \dots,\gamma_{\sigma(k-1)}I_{n_{k-1}})Q^{-1}\in\mathbb{C}^{n\times n}$, where $m_{0}+m_{1}+\cdots +m_{k-1}=m$, $n_{0}+n_{1}+\cdots+n_{k-1}=n$, $\gamma_{0}$, $\gamma_{1}$, \dots, $\gamma_{k-1}$ are distinct complex numbers, and $\sigma :\mathbb{Z}_{k}\to\mathbb{Z}_{k}= \{0,1, \dots, k-1\}$. We say that $A\in\mathbb{C}^{m\times n}$ is $(R,S_{\sigma})$-commutative if $RA=AS_{\sigma}$. We characterize the class of $(R,S_{\sigma})$-commutative matrrices and extend results obtained previously for the case where $\gamma_{\ell}=e^{2\pi i\ell/k}$ and $\sigma(\ell)=\alpha\ell+\mu \pmod{k}$, $0 \le \ell \le k-1$, with $\alpha$, $\mu\in\mathbb{Z}_{k}$. Our results are independent of $\gamma_{0}$, $\gamma_{1}$, \dots, $\gamma_{k-1}$, so long as they are distinct; i.e., if $RA=AS_{\sigma}$ for some choice of $\gamma_{0}$, $\gamma_{1}$, \dots, $\gamma_{_{k-1}}$ (all distinct), then $RA=AS_{\sigma}$ for arbitrary of …


Asymptotic Preconditioning Of Linear Homogeneous Systems Of Differential Equations, William F. Trench Dec 2010

Asymptotic Preconditioning Of Linear Homogeneous Systems Of Differential Equations, William F. Trench

William F. Trench

No abstract provided.


Characterization And Properties Of Matrices With $K$-Involutory Symmetries Ii, William F. Trench Dec 2009

Characterization And Properties Of Matrices With $K$-Involutory Symmetries Ii, William F. Trench

William F. Trench

No abstract provided.


Properties Of Multilevel Block $\Alpha$-Circulants, William F. Trench Dec 2008

Properties Of Multilevel Block $\Alpha$-Circulants, William F. Trench

William F. Trench

No abstract provided.


On Nonautonomous Linear Systems Of Differential And Difference Equations With $R$-Symmetric Coefficient Matrices, William F. Trench Dec 2008

On Nonautonomous Linear Systems Of Differential And Difference Equations With $R$-Symmetric Coefficient Matrices, William F. Trench

William F. Trench

No abstract provided.


Characterization And Properties Of Matrices With K-Involutory Symmetries, William F. Trench Dec 2007

Characterization And Properties Of Matrices With K-Involutory Symmetries, William F. Trench

William F. Trench

No abstract provided.


Absolute Equal Distribution Of The Eigenvalues Of Discrete Sturm-Liouville Problems, William F. Trench Dec 2005

Absolute Equal Distribution Of The Eigenvalues Of Discrete Sturm-Liouville Problems, William F. Trench

William F. Trench

No abstract provided.


Functional Perturbations Of Nonoscillatory Second Order Difference Equations, William F. Trench Dec 2005

Functional Perturbations Of Nonoscillatory Second Order Difference Equations, William F. Trench

William F. Trench

No abstract provided.


Characterization And Properties Of $(R,S)$-Symmetric, $(R,S)$-Skew Symmetric, And $(R,S)$-Conjugate Matrices, William F. Trench Dec 2004

Characterization And Properties Of $(R,S)$-Symmetric, $(R,S)$-Skew Symmetric, And $(R,S)$-Conjugate Matrices, William F. Trench

William F. Trench

No abstract provided.


Asymptotic Relationships Between Singular Values Of Structured Matrices Similarly Generated By Different Formal Expansions Of A Rational Function, William F. Trench Dec 2004

Asymptotic Relationships Between Singular Values Of Structured Matrices Similarly Generated By Different Formal Expansions Of A Rational Function, William F. Trench

William F. Trench

No abstract provided.


Multilevel Matrices With Involutory Symmetries And Skew Symmetries, William F. Trench Dec 2004

Multilevel Matrices With Involutory Symmetries And Skew Symmetries, William F. Trench

William F. Trench

No abstract provided.


Inverse Eigenproblems And Associated Approximation Problems For Matrices With Generalized Symmetry Or Skew Symmetry, William F. Trench Dec 2003

Inverse Eigenproblems And Associated Approximation Problems For Matrices With Generalized Symmetry Or Skew Symmetry, William F. Trench

William F. Trench

No abstract provided.


Hermitian, Hermitian R-Symmetric, And Hermitian R-Skew Symmetric Procrustes Problems, William F. Trench Dec 2003

Hermitian, Hermitian R-Symmetric, And Hermitian R-Skew Symmetric Procrustes Problems, William F. Trench

William F. Trench

No abstract provided.


Minimization Problems For (R,S)-Symmetric And (R,S)-Skew Symmetric Matrices, William F. Trench Dec 2003

Minimization Problems For (R,S)-Symmetric And (R,S)-Skew Symmetric Matrices, William F. Trench

William F. Trench

No abstract provided.


Simplification And Strengthening Of Weyl's Definition Of Asymptotic Equal Distribution Of Two Families Of Finite Sets, William F. Trench Dec 2003

Simplification And Strengthening Of Weyl's Definition Of Asymptotic Equal Distribution Of Two Families Of Finite Sets, William F. Trench

William F. Trench

No abstract provided.


An Elementary Note On Asymptotic Properties Of Toeplitz And Multilevel Toeplitz Matrices, William F. Trench Dec 2003

An Elementary Note On Asymptotic Properties Of Toeplitz And Multilevel Toeplitz Matrices, William F. Trench

William F. Trench

No abstract provided.


Spectral Distribution Of Hermitian Toeplitz Matrices Formally Generated By Rational Functions, William F. Trench Dec 2002

Spectral Distribution Of Hermitian Toeplitz Matrices Formally Generated By Rational Functions, William F. Trench

William F. Trench

No abstract provided.


A Note On Asymptotic Zero Distribution Of Orthogonal Polynomials, William F. Trench Dec 2002

A Note On Asymptotic Zero Distribution Of Orthogonal Polynomials, William F. Trench

William F. Trench

No abstract provided.


Absolute Equal Distribution Of The Spectra Of Hermitian Matrices, William F. Trench Dec 2002

Absolute Equal Distribution Of The Spectra Of Hermitian Matrices, William F. Trench

William F. Trench

No abstract provided.


Absolute Equal Distribution Of Families Of Finite Sets, William F. Trench Dec 2002

Absolute Equal Distribution Of Families Of Finite Sets, William F. Trench

William F. Trench

No abstract provided.


Linear Perturbations Of A Nonoscillatory Second Order Differential Equation Ii, William F. Trench Dec 2002

Linear Perturbations Of A Nonoscillatory Second Order Differential Equation Ii, William F. Trench

William F. Trench

No abstract provided.


Asymptotically Constant Solutions Of Functional Difference Systems, William F. Trench Dec 2001

Asymptotically Constant Solutions Of Functional Difference Systems, William F. Trench

William F. Trench

No abstract provided.


Properties Of Some Generalizations Of Kac-Murdock-Szeg"O Matrices, William Trench Jan 2001

Properties Of Some Generalizations Of Kac-Murdock-Szeg"O Matrices, William Trench

William F. Trench

No abstract provided.


Systems Of Difference Equations With Asymptotically Constant Solutions, William F. Trench Dec 1999

Systems Of Difference Equations With Asymptotically Constant Solutions, William F. Trench

William F. Trench

No abstract provided.


Conditional Convergence Of Infinite Products, William F. Trench Dec 1998

Conditional Convergence Of Infinite Products, William F. Trench

William F. Trench

No abstract provided.


Linear Asymptotic Equilibrium For Nilpotent Systems Of Difference Equations, William F. Trench Dec 1998

Linear Asymptotic Equilibrium For Nilpotent Systems Of Difference Equations, William F. Trench

William F. Trench

No abstract provided.