What can we learn from Bohemian Matrices?

An adventure in symbolic-numeric computation

Authors

  • Rob Corless School of Mathematical and Statistical Sciences Western University, London, Ontario, N6A 5B7 CanadaEditor-in-Chief, Maple Transactions https://orcid.org/0000-0003-0515-1572

DOI:

https://doi.org/10.5206/mt.v1i1.14039

Keywords:

Bohemian matrices, skew-symmetric tridiagonal matrices, rounding error, hybrid symbolic-numeric computing

Abstract

This Maple Workbook explores a new topic in linear algebra, which is called "Bohemian Matrices". The topic is accessible to people who have had even just one linear algebra course, or have arrived at the point in their course where they have touched "eigenvalues". We use only the concepts of characteristic polynomial and eigenvalue. Even so, we will see some open questions, things that no-one knows for sure; even better, this is quite an exciting new area and we haven't even finished asking the easy questions yet! So it is possible that the reader will have found something new by the time they have finished going through this workbook. Reading this workbook is not like reading a paper: you will want to execute the code, and change things, and try alternatives. You will want to read the code, as well. I have tried to make it self-explanatory.

We will begin with some pictures, and then proceed to show how to make such pictures using Maple (or, indeed, many other computational tools). Then we start asking questions about the pictures, and about other things.

Author Biography

Rob Corless, School of Mathematical and Statistical Sciences Western University, London, Ontario, N6A 5B7 CanadaEditor-in-Chief, Maple Transactions

Robert M. Corless did his B.Sc in Mathematics and Computer Science at the University of British Columbia, his M.Math at Waterloo, and his PhD at UBC. He is Emeritus Distinguished University Professor at Western University, a member of the Rotman Institute of Philosophy, the Scientific Director of The Ontario Research Center for Computer Algebra (www.orcca.on.ca) and an Adjunct Professor at the David R. Cheriton School of Computer Science, the University of Waterloo.  He is the Editor-in-Chief of Maple Transactions.

A density plot of all complex eigenvalues of a certain Bohemian family, using the Viridis colour scheme.  It looks vaguely like a reptilian pupil in a dragon's eye.

Published

2021-06-02 — Updated on 2023-03-23

Versions