Abstract
We obtain an asymptotic formula for the fourth moment of quadratic Dirichlet L-functions over \({\mathbb{F}_q[x]}\), as the base field \({\mathbb{F}_q}\) is fixed and the genus of the family goes to infinity. According to conjectures of Andrade and Keating, we expect the fourth moment to be asymptotic to \({q^{2g+1} P(2g+1)}\) up to an error of size \({o(q^{2g+1})}\), where P is a polynomial of degree 10 with explicit coefficients. We prove an asymptotic formula with the leading three terms, which agrees with the conjectured result.
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Florea, A. The fourth moment of quadratic Dirichlet L-functions over function fields. Geom. Funct. Anal. 27, 541–595 (2017). https://doi.org/10.1007/s00039-017-0409-8
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DOI: https://doi.org/10.1007/s00039-017-0409-8