On Some Weighted Average Values of L-functions

Abstract

Let $q\ge 2$ and $N\ge 1$ be integers. W. Zhang (2008) has shown that for any fixed $\epsilon> 0$, and $q^{\epsilon} \le N \le q^{1/2 -\epsilon}$, $$ \sum_{\chi \ne \chi_0} |\sum_{n=1}^N \chi(n)|^2 |L(1, \chi)|^2 = (1 + o(1)) \alpha_q q N $$ where the sum is take over all nonprincipal characters $\chi$ modulo $q$, $L(s, \chi)$ is the $L$-functions $L(1, \chi)$ corresponding to $\chi$ and $\alpha_q = q^{o(1)}$ is some explicit function of $q$. Here we show that the same formula holds in the range $q^{\epsilon} \le N \le q^{1 -\epsilon}$.