MathOverflow is a question and answer site for professional mathematicians. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Good day,

Could someone please give a reference about how to use Fox Calculus to compute the cohomology of a $2$-group $G$ with coefficients in a submodule of $\oplus^n F_2[G]$.

Is there a formula to count Fox derivations? $G\to F_2[G]$.


share|cite|improve this question

A 2-group? You are tough cookie. For a knot group, Crowell-Fox's book on knot theory does a nice job. In general its just an observation about the module structure of the CW groups of a normal covering space of your CW complex, where you are working over the group ring of the deck transformations. It only works for computing the 0th and 1st homology groups. Maybe you meant two complex. :) In which point it works for every homology group.

share|cite|improve this answer
Could 2-group be the p=2 case of a p-group, perhaps? That was my first thought, seeing as the coefficient module lives inside a group ring over the 2-element field – Yemon Choi Mar 19 '10 at 22:14

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.