Assume $G$ is a random finite group, and $N$ is a normal subgroup of $G$.
How do I construct a representation of $G$ from an existing representation $G/N$?
So far I have written:
$\varphi:G/N\rightarrow GL(V)\\
\psi:G\rightarrow GL(W)$
with $V,W$ vector spaces. Then we need to construct $\psi$ from $\varphi$.
I also wrote this, however I do not know if I can do anything with this.
$$\begin{align}
&G/N\xrightarrow{\varphi}GL(V)\\
&\downarrow\hspace{2cm}\downarrow\\
&\hspace{0.1cm}G\hspace{0.5cm}\xrightarrow{\psi}GL(W)
\end{align}$$
That's a very natural definition. Define $\psi:G\to GL(V)$ by $\psi(g)=\varphi(gN)$. It is easy to check that this is a homomorphism of groups, and thus a representation of $G$.