Can anyone suggest any good books on learning path integration? Maybe even just functional integration? I understand that there may be good introductions in QFT books, but are there any good mathematical approaches to these concepts contained in other books? Please tell me if just reading good QFT books will suffice. Thanks.
If you just want to use them, reading some good QFT books will serve you just fine. However, even in the best of QFT books, usually a lot of things are swept under the carpet (most notably: some possible infinities in the integration measure). If you want a mathematically rigorous treatment, I cannot really help you, except to refer you to the ArXiv (www.arxiv.org). If you use the search form and search for "path integral" in the title and check only the Mathematics box, you might find some interesting articles. For example, in math-ph/0012017 I find So you might check out those references, for starters.