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Number of Points on the Projective Curves aYl=bXl+cZl and aY2l=bX2l+cZ2l Defined over Finite Fields, l an Odd Prime

✍ Scribed by N. Anuradha; S.A. Katre


Publisher
Elsevier Science
Year
1999
Tongue
English
Weight
201 KB
Volume
77
Category
Article
ISSN
0022-314X

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✦ Synopsis


The number of points on the curve aY e =bX e +c (abc{0) defined over a finite field F q , q#1 (mod e), is known to be obtainable in terms of Jacobi sums and cyclotomic numbers of order e with respect to this field. In this paper, we obtain explicitly the Jacobi sums and cyclotomic numbers of order e=l and e=2l over finite fields F q , q= p : #1 (mod e), for odd primes l and any prime p such that the order of p modulo l is even. Contrary to the case p#1 (mod e) considered in the literature, we have obtained these results solely in terms of q and l. We apply these results to evaluate the number of F q n -rational points on the non-singular projective curves aY l =bX l +cZ l and aY 2l =bX 2l +cZ 2l (abc{0) defined over finite fields F q , with conditions on q, p, and l as above. Using these evaluations, we obtain explicitly the `-function of the former curve aY l =bX l +cZ l defined over F q as a rational function in the variable t. Thereby we corroborate the Weil conjectures (now theorems) for this concrete class of curves.

1999 Academic Press J e (i, j)= : v # F q / i (v) / j (v+1)= :

v # F q "[0, &1]

`i ind # (v)+ j ind # (v+1) ,