Shanks' bias in function fields

Abstract

We study the function field analogue of Shanks bias. For Liouville function $\lambda(f)$, we compare the number of monic polynomials $f$ with $\lambda(f) \chi_m(f) = 1$ and $\lambda(f) \chi_m(f) = -1$ for a nontrivial quadratic character $\chi_m$ modulo a monic square-free polynomial $m$ over a finite field. Under Grand Simplicity Hypothesis (GSH) for $L$-functions, we prove that $\lambda \cdot \chi_m$ is biased towards $+1$. We also give some examples where GSH is violated.