Let $K$ be a finite extension of $\mathbb{Q}_p$ with ring of integers $A$. Let $F$ be a $p$-divisible group and $T$ be the Tate module. Consider the vector space $V=T \otimes_{\mathbb{Q}_p} C$, where $C=\widehat{\bar{K}}$. 

Let $G$ be the image of the Galois group $\text{Gal}(\bar{K}/K)$ in $\text{Aut}(V)$ and $\mathfrak{g}$ be the Lie algebra of $G$.


[Serre](https://link.springer.com/chapter/10.1007/978-3-642-87942-5_10) proved in **Theorem 5**:

> *If $F$ is 1-dimensional formal group, then the image of $\text{Gal}(\bar{K}/K)$ is open in $\text{Aut}(V)$, where $V=T_pF \otimes C$.*

This is consequence of **Theorem 4** of the same paper, which says:

> If we assume the following hypotheses on $F$:
> 
> - $V$ is an semi-simple $G$-module
> - $\text{End}(F)=\mathbb{Z}_p$
> - The dimensions of $n_1$ and $n_0$ of $F$ and its dual group $F'$ are $\geq 1$ and coprime.
> 
> Then, $G_{alg}=GL_V$, $\mathfrak{g}=\text{End}(V)$ and $G$ is an **open**
> subgroup of $\text{Aut}(V)$,
> where $G_{alg}$ is called an envelope of $\text{Gal}(\bar{K}/K)$, which is the smallest algebraic subgroup of the general linear group $GL_V$ of $V$.

**My question:**

Can we extend the Theorem 5 (the first result above) to higher-dimensional formal groups, provided enough conditions? 

---

Serre proved in **Proposition 8** that if $F$ is of dimension 1, then $V$ is a simple $\mathfrak{g}$-module. Thus, the *hypothesis* of Theorem 4 (the second result above) is automatically satisfied because $G$ is simple if its Lie algebra $\mathfrak{g}$ is simple.

So I think the above Theorem 5 extends to higher-dimensional formal groups $F$ as well, provided $V=T_F \otimes C$ is semi-simple $G$-module or $\mathfrak{g}$-module. 

However, not all formal groups a $p$-divisible groups. So we have to make sure the formal group $F$ is indeed a $p$-divisible group.

I hope I will get some help to clarify my understanding in the above issue.