Talk:Formal group law
|WikiProject Mathematics||(Rated Start-class, Mid-importance)|
This is a great introduction; if someone could expand it, that would be great!
Not a group object?
Isn't a formal group a group object in the category of formal schemes? Spakoj 12:34, 2 May 2006 (UTC)
Over the rational numbers, there is an isomorphism from the additive formal group law to the multiplicative one, given by exp(x) − 1.
I would mention here that exp(x) is seen here as a formal power series over the rationals, exp(x)=1+x+x^2/2+x^3/6+.. and also that log(x) is seen as a formal power series over the rationals. This would make it clear why you don't need to work over the field of real numbers. — Preceding unsigned comment added by 126.96.36.199 (talk) 14:22, 8 October 2015 (UTC)