4 citations · 10 across the 10 of their papers we have counts for
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The numerical range of some periodic tridiagonal operators is the convex hull of the numerical ranges of two finite matrices
Benjamín A. Itzá-Ortiz, Rubén A. Martínez-Avendaño, Hiroshi Nakazato
In this paper we prove a conjecture stated by the first two authors establishing the closure of the numerical range of a certain class of -periodic tridiagonal operators as th…
The numerical range of a periodic tridiagonal operator reduces to the numerical range of a finite matrix
Benjamín A. Itzá-Ortiz, Rubén A. Martínez-Avendaño, Hiroshi Nakazato
In this paper we show that the closure of the numerical range of an -periodic tridiagonal operator is equal to the numerical range of a complex matrix.
Generalized cell structures
Ana Hernández-Dávila, Benjamín A. Itzá-Ortiz, Rocío Leonel-Gómez
Cell structures were introduced by W. Debski and E. Tymchatyn as a way to study some classes of topological spaces and their continuous functions by means of discrete approximation…