This is a question that was asked a few years ago at Does there exist an holomorphic function such that $|f(z)|\geq \frac{1}{\sqrt|z|}$?.
Does there exist a function $f$ holomorphic on $\mathbb{C} \setminus \{ 0 \}$ such that $|f(z)|\geq \frac{1}{\sqrt|z|}$ for all $z\in\mathbb C \setminus \{0\}$?
While i have understood the answer mentioned in the link, I wanted to know whether we can apply the Maximum Modulus Theorem(MMT) to solve this. I tried as follows:
Let the domain of $f$ be the punctured open disc, $|z| < 1, z \neq 0$. The boundary for this domain is $|z| = 1$ and $z = 0$. By MMT, if $f$ did indeed exist satisfying the given conditions, then the maximum of $f$, if it exists, must exist at the boundary of the domain : in this case at $|z|=1$ as $z=0$ is not a part of the domain. But we see that $|f|$ blows up as we get arbitrarily close to $0$. Therefore, the maximum doesn't occur at $|z|=1$ for sure. My question is, does a maximum occur anywhere at all, that I may then conclude that, by MMT, such an $f$ canNOT exist?
proof-verification
to your tags. – José Carlos Santos Sep 25 '19 at 10:27