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Cristina Manzaneda

Publications and source records attributed to Cristina Manzaneda.

3 recordsLinked to original sources

On properties of the conformal circulant matrices

In this paper, we introduce and study conformal permutation matrices. In particular, for a permutation $π_s\in S_n$, we define the corresponding conformal permutation matrix $H_{π_s}$ and show that its $d-$th power, where $d=n/\gcd(s,n)$, is a diagonal block matrix whose blocks are products of certain matrix blocks $h_i$. We further show that these diagonal blocks share a common subset of eigenvalues and prove that $H_{π_s}$ is block-diagonalizable. We also introduce the notion of conformal circulant matrix and investigate its eigenvalues. Finally, we establish a necessary and sufficient condition for a rectangular matrix to be conformal circulant.

math.CO

Block matrices and Guo's Index for block circulant matrices with circulant blocks

In this paper we deal with circulant and partitioned into $n$-by-$n$ circulant blocks matrices and introduce spectral results concerning this class of matrices. The problem of finding lists of complex numbers corresponding to a set of eigenvalues of a nonnegative block matrix with circulant blocks is treated. Along the paper we call realizable list if its elements are the eigenvalues of a nonnegative matrix. The Guo's index $λ_0$ of a realizable list is the minimum spectral radius such that the list (up to the initial spectral radius) together with $λ_0$ is realizable. The Guo's index of block circulant matrices with circulant blocks is obtained, and in consequence, necessary and sufficient conditions concerning the NIEP, Nonnegative Inverse Eigenvalue Problem, for the realizability of some spectra are given.

math.SP