Isn't most of their music... Actually math based in some way? I remember hearing that somewhere... It was like trig or highly advanced algebra...
In my opinion, people who say that kind of stuff usually don't know what they're talking about. As far as I know, the only particularly mathematical thing that Meshuggah do is use odd time signatures and polyrythms. From a mathematical point of view, it's no more advanced than fractions. I HIGHLY doubt that Meshuggah use math for anything else, and I think you'll find that the more one conciously uses advanced math to compose music, the less listenable it is. You can find complex patterns in a lot of music if you go looking for it, but that doesn't mean that composers sit down an solve equations to make it. There is also a relationship between trigonometry and music, but it's mainly interesting from an analytic point of view, and isn't really something most people think of when making it. I could go into more detail, but I think I've proably said too much already!