[Math] Does an analytic function maps a simple connected region into a simple connected region

complex-analysisgeneral-topology

Suppose $f$ is analytic, say, in $\mathbb{C}$, and suppose $\Omega$ is a bounded simple connected open domain whose boundary we denote as $\Gamma$, then is $f(\Omega)$ also a simple connected domain whose boundary is $f(\Gamma)$?

I think $f(\Omega)$ is also connected becasue the continuity of $f$ suffices,
but I'm not sure whether $f(\Omega)$ is simple connected and whether $f(\Gamma)$ will be the boundary of the domain.

Sorry for the above too simple question…

Now I put an additional condition on $f$, assuming that $f$ maps $\Gamma$ injectively into $f(\Gamma)$, then what can we say about $f(\Omega)$ ?
Or, what if $f$ is injective on $\overline{\Omega}$ ?

Best Answer

As @nsrt indicates, the set $\{ z \mid \Im(z) \gt 0, 1 \lt |z| \lt 2 \}$ maps under $z\mapsto z^3$ to $\{|z| \lt 8\}\setminus \{|z|\le 1\}$, which is not simply connected.