On formal group laws over the quotients of Lazard's ring (Q2312708)

Let \[F(x,y)=\sum_{i,j} a_{i,j} x^iy^j\] be the universal formal group law over the Lazard ring \(\Lambda=\mathbb{Z}[x_1,x_2,x_3,\dots]\), \(|x_i|=2i\). Denote by \[ \omega(x)=\frac{\partial F(x,y)}{\partial y}(x,0)=1+\sum_{i\geq 1} w_i x^i \] the invariant differential form of \(F\). Define a formal power series \(A(x,y)\) by \[ A(x,y)=\sum_{i,j} A_{i,j} x^i y^j=F(x,y)(x\omega(y)-y\omega(x)). \] In the paper under review the formal group laws over the quotient rings \[ \Lambda_n=\Lambda/(A_{n+1,j}; \;j>n+1) \] are studied. It is shown that \[ \Lambda_n\otimes \mathbb{Q}\cong \mathbb{Q}[p_1,\dots,p_{2n}], \] with \(|p_i|=2i\).