2013/03/03 by Hou, Xiang-dong
#11T06 #11T55 #FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.1303.0568
Let q>2 be a prime power and f=-\tt x+t\tt xq+\tt x2q-1, where t∈\Bbb Fq^*. We prove that f is a permutation polynomial of \Bbb Fq2 if and only if one of the following occurs: (i) q is even and Trq/2(\frac 1t)=0; (ii) q≡ 1\pmod 8 and t2=-2.