I'll start with a complaint about the Tetratorus. First, I still think it should be called a tritorus or a 3-torus, but I'll wait for Rob to come back before we argue about that.
The other thing is the surcell volume and bulk. I changed it from 4pi R r to 4pi R r a, and someone changed it back saying
Trust me, it isn't multiplied by a - there's a complex formula that cancels it out.
Who said that, and what's this complex formula that somehow gives you a volume measured in square meters?
Anyway, I've just calculated the integral directly with mathematica, and I get:
V = 8 pi^3 a r R
B = 4 pi^3 a^2 r R
So it turns out we were both wrong.