Sun’s circular-permutation conjecture over finite fields

Establish whether, for every prime power q>7 and every a_0\in\mathbb{F}_q, there exists a circular permutation (a_1,\dots,a_{q-1}) of all elements of \mathbb{F}_q^* such that each of a_0+a_1a_2, a_0+a_2a_3, \dots, a_0+a_{q-2}a_{q-1}, and a_0+a_{q-1}a_1 is a primitive element of \mathbb{F}_q, including the cases not covered by the paper’s proof for q>18,888,871.

Background

The paper reformulates Sun’s conjecture as a Hamiltonicity problem for the graph G_{q,a_0} whose vertex set is \mathbb{F}_q* and in which distinct vertices x and y are adjacent precisely when a_0+xy is primitive. A Hamilton cycle in this graph gives the required circular permutation.

The paper proves the conjecture for every prime power q>18,888,871 and proves the a_0=0 case for q>4. Consequently, the general conjecture as stated remains unresolved for the parameter range not covered by those results, particularly 7<q\le18,888,871 with a_0\ne0.

References

In this paper, we study another conjecture of Sun Conjecture 3.8.

\begin{conjecture} \label{conj:main} Let $\mathbb{F}q$ be a finite field with $q > 7$. For any given element $a_0 \in \mathbb{F}_q$, there exists a circular permutation $(a_1, \dots, a{q-1})$ of all elements of $\mathbb{F}q*$ such that $$ a_0 + a_1 a_2, \quad a_0 + a_2 a_3, \quad \dots, \quad a_0 + a{q-2} a_{q-1}, \quad a_0 + a_{q-1} a_1 $$ are primitive elements of $\mathbb{F}_q$. \end{conjecture}

— A Conjecture on Circular Permutations over Finite Fields  (2610.06289 - Luo et al., 5 Oct 2026) in Section 1, Conjecture 1 (equation label conj:main)