May 18 – 22, 2026
Virginia Tech
America/New_York timezone

On the $k$-numerical ranges of matrices

May 18, 2026, 5:00 PM
25m
Goodwin Hall 244

Goodwin Hall 244

Minisymposium Talk Numerical Ranges and Numerical Radii Numerical Ranges and Numerical Radii

Speaker

Kennett Dela Rosa (University of the Philippines Diliman)

Description

This study considers some problems involving the $k$-numerical range. Following the idea of the zero-dilation index, the notion of the zero-trace index is introduced, which is defined as the largest zero-trace compression of a matrix. Alternative characterization of the zero-trace index is given, and zero-trace indices of certain classes of matrices are identified. The study also considers recent results on the numerical range of cyclic shift matrices. A recent solution to a conjecture proved that a certain arrangement of the weights of a given cyclic shift matrix maximizes the classical numerical range. This work explores whether analogous optimal arrangements exist for the $k$-numerical range.

Author

Kennett Dela Rosa (University of the Philippines Diliman)

Presentation materials

There are no materials yet.