I'd like to learn more about the indefinite orthogonal group but can't find a good book which covers the topic. The minimum would be that it covers the basic theorems and proofs concerning the group (such as. $O(p,q)\cong O(q,p), \forall p,q\in \mathbb{N}$, and so on), ideally it would also have some links to physics and explain why the group is important. If the book would cover the group just as a part of a section or something like that it would be fine as well.
Can anyone recommend a book that goes in that direction?
Thanks in advance, Sito.