Start with the library of congress classification system. It'll get you 90 percent of the way there for 10% of the effort.

(Classification systems are very much an information science topic... and they're pretty damn important. Along those same lines - you'll want to think carefully and critically about what is seen as canonical knowledge, and what's "in" those fields, versus what is perceived as "utter crackpot bullshit" that nobody takes seriously. The fields you've mentioned ALL have a significant amount of bleed at the edges - where does math become mathematical physics and then 'really physics' ... it's just not that easy.)

Fanboy comment: just google Eugene Garfield. Have fun!