My main interest is Quantum Field Theory, Gauge Theories and Quantum Loop Gravity. On the way, I needed to understand Lie groups. I found the available textbooks somewhat impenetrable so I engaged a tutor, Pietro Longhi, who was able to peal back some of the layers of obscurity. The more I learned, the more I became convinced that I could write something that would be a more accessible introduction to Lie groups than the texts that I had found.

During this time, I found Bob Klauber's Student Friendly Quantum Field Theory text. In my opinion, he succeeded in making QFT accessible to a new student in a way that no other text has. So I decided to use some of his techniques to make Lie algebras more accessible. My task is more modest in that I just want to aquaint the new student with some of the most important ideas prior to engagement in a more conventional group theory course or self study.

My background is an amateur physicist with a BS in Engineering Physics from Cornell University, 20 years of engineering and scientific computer programming and 20 years as a property-casualty actuary. Now, I am blissfully retired.

Douglas McKenzie

## Why a Paper About Lie Groups and Algebras?