A note on exceptional characters and non-vanishing of Dirichlet L-functions
: Cech Martin, Matomäki Kaisa
Publisher: SPRINGER HEIDELBERG
: 2023
: Mathematische Annalen
: MATHEMATISCHE ANNALEN
: MATH ANN
: 10
: 0025-5831
: 1432-1807
DOI: https://doi.org/10.1007/s00208-023-02667-x
: https://link.springer.com/article/10.1007/s00208-023-02667-x
: https://research.utu.fi/converis/portal/detail/Publication/180427980
We study non-vanishing of Dirichlet L-functions at the central point under the unlikely assumption that there exists an exceptional Dirichlet character. In particular we prove that if ψ is a real primitive character modulo D ∈ N with L(1,ψ) ≪ (log D)−25−ε, then, for any prime q ∈ [D300, DO(1)], one has L(1/2, χ) ≠ 0 for almost all Dirichlet characters χ (mod q).