Some results about permutation properties of a kind of binomials over finite fields

Permutation polynomials have many applications in finite fields theory, coding theory, cryptography, combinatorial design, communication theory, and so on. Permutation binomials of the form $x^{r}(x^{q-1}+a)$ over $mathbb{F}_{q^2}$ have been studied before, K. Li, L. Qu and X. Chen proved that they are permutation polynomials if and only if $r=1$ and $a^{q+1} ot=1$. In this paper, we consider the same binomial, but over finite fields $mathbb{F}_{q^3}$ and $mathbb{F}_{q^e}$. Two different kinds of methods are employed, and some partial results are obtained for them.