I am trying to understand whether something non trivial is known about the following $$\sum_{n \leq x} \mu(n) \chi(n),$$ as a function of $x$.
Here $\chi$ is a Dirichlet character modulo $q$ and $q > (\log x)^2$ (for example).
I am trying to understand whether something non trivial is known about the following $$\sum_{n \leq x} \mu(n) \chi(n),$$ as a function of $x$.
Here $\chi$ is a Dirichlet character modulo $q$ and $q > (\log x)^2$ (for example).