Kohl's primitive-root permutation sign conjecture

From papers

Let pp be an odd prime, let gg be a primitive root modulo pp, and define σg\sigma_g on Z/pZ={0,1,,p1}\mathbb Z/p\mathbb Z=\{0,1,\ldots,p-1\} by

σg(b):=gb\sigma_g(b):=g^b

for b{1,,p1}b\in\{1,\ldots,p-1\}, with σg(0)=0\sigma_g(0)=0. Let Rp\mathcal R_p be the set of primitive roots modulo pp, and regard σg\sigma_g as a permutation of Z/pZ\mathbb Z/p\mathbb Z. Kohl's conjecture. (i) If p1(mod4)p\equiv1\pmod4, then

#{gRp:sgn(σg)=1}=#{gRp:sgn(σg)=1}.\#\{g\in\mathcal R_p:\operatorname{sgn}(\sigma_g)=1\}=\#\{g\in\mathcal R_p:\operatorname{sgn}(\sigma_g)=-1\}.

(ii) If p3(mod4)p\equiv3\pmod4, then for every gRpg\in\mathcal R_p,

sgn(σg)(p12)!(modp).\operatorname{sgn}(\sigma_g)\equiv-\left(\frac{p-1}{2}\right)!\pmod p.

The problem was posed by S. Kohl in 2018. The supplied status evidence says that this conjecture was confirmed by Ladisch and Petrov.

Progress summary

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

Sources & referencesView supporting material

Primary source

Li-Yuan Wang and Hai-Liang Wu, “Applications of Lerch's theorem and permutations concerning quadratic residues”, arXiv:1810.03006 (2019).

Solutions 0

No solutions have been posted yet.