Ok. I purchased the book. However, I am having a hard time following what the author is even trying to explain. It could be the language or my mathematical immaturity - I have no idea. I guess I will just keep trying...
For example, can anybody tell me what the author is trying to say and the logic behind what he is saying in the following two paragraphs?
https://photos.app.goo.gl/ALdh4vV7PwsT6dQz2
https://photos.app.goo.gl/o12tObtXHnmLMI1W2
I am pretty sure I do not have the prerequisite to read this book effectively, but I can't help but thinking, the presentation may be quite fuzzy!
What background do I need to read and understand this book? I know QM (from Sakurai and a few others). I do understand SR and GR. However, I do not know much of group theory or lie algebra or a ton of Hilbert Space formalism.
If you are looking for a context in which the author explains the paragraphs that I mentioned, you could look at this excerpt.
http://www.beck-shop.de/fachbuch/leseprobe/9780521632652_Excerpt_001.pdf