This may be trivial but I cannot find it. Given an elliptic curve, $C$ over $R$ with chosen parametrization $R\to \mathbb{A}^5\_{\mathbb{Z}}=Spec(A)$, is there a way to compute coefficients of the associated formal group law, assuming this is enough information to coordinatize it. I would assume that the coefficients are rational or at least analytic function of our parametrization, though I am not making any headway. Can anyone enlighten me on this issue?


Edit: When considering the pullback of $Spec(L)\to \mathcal{M}\_{FG}$ along $\mathcal{M}\_{Ell}\to \mathcal{M}\_{FG}$, we get $Spec(A[b\_1, b\_2, ...])$ so that the zero morphism should give us a map $Spec(A)\to Spec(L)$, which should be what we want. Computation of this map though, is not clear to me.



Is it possible to compute coefficients of the formal group of an elliptic curve?
I assume you mean Weierstrass parametrization. Then $-x/y$ is the standard coordinate near 0, and the relevant formulas can be found in Silverman's book on elliptic curves. 


