arXiv subjects

Joáo da Providéncia

Publications and source records attributed to Joáo da Providéncia.

2 recordsLinked to original sources

arXiv2021

On Kippenhahn curves and higher-rank numerical ranges of some matrices

The higher rank numerical ranges of generic matrices are described in terms of the components of their Kippenhahn curves. Cases of tridiagonal (in particular, reciprocal) 2-periodic matrices are treated in more detail.

math.FA↗

arXiv2020

Kippenhahn curves of some tridiagonal matrices

Tridiagonal matrices with constant main diagonal and reciprocal pairs of off-diagonal entries are considered. Conditions for such matrices with sizes up to 6-by-6 to have elliptical numerical ranges are obtained.

math.FA↗