Zobrazeno 1 - 10
of 20
pro vyhledávání: '"Pietro Paparella"'
Autor:
Andrew Nickerson, Pietro Paparella
Publikováno v:
University of Wyoming Open Journals
McDonald and Paparella [Linear Algebra Appl. 498 (2016), 145-159] gave a necessary condition on the structure of the Jordan chains of h-cyclic matrices. In this work, that necessary condition is shown to be sufficient. As a consequence, we provide a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7d739390212576934ef52c26509b1192
https://doi.org/10.13001/ela.2022.7019
https://doi.org/10.13001/ela.2022.7019
Autor:
Benjamin J. Clark, Pietro Paparella
Publikováno v:
Linear Algebra and its Applications. 637:110-118
In further pursuit of a solution to the celebrated nonnegative inverse eigenvalue problem, Loewy and London [Linear and Multilinear Algebra 6 (1978/79), no.~1, 83--90] posed the problem of characterizing all polynomials that preserve all nonnegative
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2311786955bcb0fc1af10685bbf70093
https://doi.org/10.1016/j.laa.2021.12.007
https://doi.org/10.1016/j.laa.2021.12.007
Publikováno v:
University of Wyoming Open Journals
An invertible matrix is called a Perron similarity if one of its columns and the corresponding row of its inverse are both nonnegative or both nonpositive. Such matrices are of relevance and import in the study of the nonnegative inverse eigenvalue p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1b972e9989490da455389826d9cf3c8b
https://doi.org/10.13001/ela.2022.6697
https://doi.org/10.13001/ela.2022.6697
Autor:
Pietro Paparella
Publikováno v:
Notes on Number Theory and Discrete Mathematics. 27:119-122
In this note, it is shown that if \ell and m are positive integers such that \ell > m, then there is a Perron number \rho such that \rho^n + (\rho + m)^n = (\rho + \ell)^n. It is also shown that there is an aperiodic integer matrix C such that C^n +
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::bcc4a015b83c080fcb3a8b96e20871e8
https://doi.org/10.7546/nntdm.2021.27.3.119-122
https://doi.org/10.7546/nntdm.2021.27.3.119-122
Autor:
Pietro Paparella
Publikováno v:
Notes on Number Theory and Discrete Mathematics. 25:22-29
Given integers $\ell > m >0$, we define monic polynomials $X_n$, $Y_n$, and $Z_n$ with the property that $��$ is a zero of $X_n$ if and only if the triple $(��,��+m,��+\ell)$ satisfies $x^n + y^n = z^n$. It is shown that the irreducib
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5f924e33ff7085cab15ee9a0d40a621c
https://doi.org/10.7546/nntdm.2019.25.2.22-29
https://doi.org/10.7546/nntdm.2019.25.2.22-29
Autor:
Amber R. Thrall, Pietro Paparella
Publikováno v:
Linear Algebra and its Applications. 566:183-198
In this work, the real nonnegative inverse eigenvalue problem is solved for a particular class of permutative matrix. The necessary and sufficient condition there is also shown to be sufficient for the symmetric nonnegative inverse eigenvalue problem
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::d0b169fec45905496954281e8c8f66bd
https://doi.org/10.1016/j.laa.2018.12.030
https://doi.org/10.1016/j.laa.2018.12.030
Autor:
Pietro Paparella
Publikováno v:
Special Matrices, Vol 7, Iss 1, Pp 213-217 (2019)
An elementary proof of a fundamental result on doubly stochastic matrices in Frobenius normal form is given. This result is used to establish several well-known results concerning permutations, including a theorem due to Ruffini.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2aa576ae37d54f0a65edc0440f126e38
https://doi.org/10.1515/spma-2019-0015
https://doi.org/10.1515/spma-2019-0015
Autor:
Pietro Paparella, Charles R. Johnson
The Gauss--Lucas and B\^{o}cher--Grace--Marden theorems are classical results in the geometry of polynomials. Proofs of the these results are available in the literature, but the approaches are seemingly different. In this work, we show that these th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::749607c6112824f0ab66637daddc924d
Autor:
Pietro Paparella, Judith J. McDonald
Publikováno v:
Linear Algebra and its Applications. 498:145-159
Arising from the classification of the matrix-roots of a nonnegative imprimitive irreducible matrix, we present results concerning the Jordan chains of an $h$-cyclic matrix. We also present ancillary results applicable to nonnegative imprimitive irre
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::59708ab3e77b851c66fb43a570a66c8a
https://doi.org/10.1016/j.laa.2015.02.029
https://doi.org/10.1016/j.laa.2015.02.029
The elliptical range theorem asserts that the field of values (or numerical range) of a two-by-two matrix with complex entries is an elliptical disk, the foci of which are the eigenvalues of the given matrix. Many proofs of this result are available
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c1127f0d6d43929eaa7b7f7acce57237
http://arxiv.org/abs/1807.04268
http://arxiv.org/abs/1807.04268