@article{50f765fe4fad404e9a1049c213088bb7,
title = "Nonparallel flat portions on the boundaries of numerical ranges of 4-by-4 nilpotent matrices∗",
abstract = "The 4-by-4 nilpotent matrices whose numerical ranges have nonparallel flat portions on their boundary that are on lines equidistant from the origin are characterized. Their numerical ranges are always symmetric about a line through the origin and all possible angles between the lines containing the flat portions are attained.",
keywords = "Nilpotent matrices, Numerical ranges",
author = "Mackenzie Cox and Grewe, {Weston M.} and Hochrein, {Grace K.} and Patton, {Linda J.} and Spitkovsky, {Ilya M.}",
note = "Funding Information: Acknowledgments. The first four authors were supported by the Bill and Linda Frost Fund. The fifth author was supported in part by the Faculty Research funding from the Division of Science and Mathematics, NYUAD. Publisher Copyright: {\textcopyright} 2021, International Linear Algebra Society. All rights reserved.",
year = "2021",
doi = "10.13001/ela.2021.5785",
language = "English (US)",
volume = "37",
pages = "504--523",
journal = "Electronic Journal of Linear Algebra",
issn = "1081-3810",
publisher = "International Linear Algebra Society",
}