Extreme Euler–Kronecker constants of quadratic fields

Determine whether the extreme values of the Euler–Kronecker constants of quadratic fields, as the fundamental discriminant ranges over values satisfying |D|\le x, are asymptotic to \log\log x+\log\log\log x+O(1) for both signs.

Background

For a quadratic field K=\mathbb{Q}(\sqrt{D}) with fundamental discriminant D, the Euler–Kronecker constant is expressed in terms of the logarithmic derivative of the associated quadratic Dirichlet L-function. The paper recalls unconditional and conditional lower bounds showing that, for infinitely many discriminants, both positive and negative extreme values reach at least the order \log\log |D|, with an additional \log\log\log |D| term under GRH.

The recalled conjecture concerns the optimal order of the maximum of \pm\gamma_{\mathbb{Q}(\sqrt{D})} over fundamental discriminants with |D|\le x. The paper proves conditional lower bounds of the conjectured order under GRH, but does not establish the corresponding upper bounds or the full asymptotic characterization.

References

They also conjectured that the extreme values of $\gamma_{\mathbb{Q}(\sqrt{D})}$, as $D$ ranges over fundamental discriminants with ${D} \leq x$, satisfy

\max_{D} \leq x} \pm \gamma_{\mathbb{Q}(\sqrt{D})} = \log \log x +\log \log \log x + O(1).

Extreme values of Euler-Kronecker constants of cubic abelian fields  (2609.18569 - Toma, 16 Sep 2026) in Section 1, Introduction