Spectrally arbitrary zero–nonzero patterns of order 4

Abstract

In this article the authors characterize all the 4×4 zero–nonzero patterns that are spectrally arbitrary. Several observations and conjectures are presented for the n × n case.

Keywords:

• Spectrally arbitrary
• Zero–nonzero patterns
• Sign patterns

Keywords:

• AMS Subject Classifications:15A18
• 15A48

Acknowledgment

The authors would like to thank the anonymous referee for carefully reading through our article and making several helpful suggestions.