2024/09/19 by Basak, Debmalya
#FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.2409.12474
Assuming the Generalized Riemann Hypothesis, it is known that at least half of the central values L((1)/(2),χ) are non-vanishing as χ ranges over primitive characters modulo q. Unconditionally, this is known on average over both χ modulo q and Q/2 ≤ q ≤ 2Q. We prove that for any δ>0, there exist η1,η2>0 depending on δ such that the non-vanishing proportion for L((1)/(2),χ) as χ ranges modulo q with q varying in short intervals of size Q1-η1 around Q and in arithmetic progressions with moduli up to Qη2 is larger than (1)/(2)-δ. Furthermore, by studying the one-level density of low-lying zeros of L(s, χ), we show that under the Generalized Riemann Hypothesis, non-vanishing proportions exceeding (1)/(2) can be obtained while still averaging over short ranges of q.