Zhang's moment conjecture for quadratic Gauss sums weighted by L-functions

Let pp be prime, let nn be an integer, and for a Dirichlet character χmodp\chi\bmod p define the generalized quadratic Gauss sum

G(n,2,χ;p)=a=1pχ(a)e(na2p),G(n,2,\chi;p)=\sum_{a=1}^{p}\chi(a)e\left(\frac{na^2}{p}\right),

where e(y)=e2πiye(y)=e^{2\pi i y}. Let χ0\chi_0 denote the principal character modulo pp, let mm be a positive integer, and define

C=p[1+(21)242p2+(42)244p4++(2mm)242mp2m+],C=\prod_p\left[1+\frac{\binom{2}{1}^2}{4^2p^2}+\frac{\binom{4}{2}^2}{4^4p^4}+\cdots+\frac{\binom{2m}{m}^2}{4^{2m}p^{2m}}+\cdots\right],

where the product is over all primes. Zhang's conjecture. For all positive integers mm,

χχ0G(n,2,χ;p)2mL(1,χ)CχmodpG(n,2,χ;p)2m,p+.\sum_{\chi\neq\chi_0}|G(n,2,\chi;p)|^{2m}|L(1,\chi)|\sim C\sum_{\chi\bmod p}|G(n,2,\chi;p)|^{2m},\qquad p\to+\infty.

This conjecture predicts an asymptotic relation between moments of quadratic Gauss sums weighted by the values of Dirichlet LL-functions and the corresponding unweighted character sum. The source attributes it to Zhang and gives no evidence of a resolution.

Sources & referencesView supporting material

Primary source

Nilanjan Bag, “Moment of Kummer sums weighted by L-functions”, arXiv:2401.13580 (2024).

Additional references

3 papers in this index state this conjecture (2021–2024). The statement above is taken from the most recent of them; the others are arXiv:2104.09888, arXiv:2104.10023.

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.