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arXiv · 2610.41458

Irrationality of values of $L$-functions for real Dirichlet characters

Veekesh Kumar·Riccardo Tosi
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Abstract

Let $χ$ be a non-trivial real Dirichlet character and $s$ be a sufficiently large integer. In this paper, we prove that among the first $s$ non-critical special values of the Dirichlet $L$-function associated with $χ$ at least $c\sqrt{\frac{s}{\log s}}$ are irrational, where $c$ is a constant independent of $s$. This is a substantial improvement on work of Fischler when $4$ divides the conductor of $χ$. Otherwise, our constant improves on work of Mistiaen. The proof adapts some techniques of Lai and Yu for odd zeta values to the case of $L$-functions. The lack of positivity arguments is overcome by applying an irrationality criterion by Lai and Sprang originating from the $p$-adic setting.

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Veekesh Kumar, Riccardo Tosi. 2026-10-30. Irrationality of values of $L$-functions for real Dirichlet characters. https://arxiv.org/abs/2610.41458

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