Abstract :
Let l be an odd prime number and p, q be two prime numbers ≡ 1 (mod l). If χ, χ′ (resp. ψ, ψ′) are multiplicative characters of order l on the finite field Fp (resp. Fq), then the corresponding Jacobi sums J(χ, χ′) and J(ψ, ψ′) satisfy the reciprocity relation [formula] where (−) denotes the lth power residue symbol over the cyclotomic field of lth roots of unity.