TY - JOUR

T1 - Del Pezzo surfaces over finite fields and their Frobenius traces

AU - Banwait, Barinder

AU - Fité, Francesc

AU - Loughran, Daniel

PY - 2018

Y1 - 2018

N2 - Let S be a smooth cubic surface over a finite field q. It is known that #S( q) = 1 + aq + q2 for some a ∈ {−2, −1, 0, 1, 2, 3, 4, 5, 7}. Serre has asked which values of a can arise for a given q. Building on special cases treated by Swinnerton–Dyer, we give a complete answer to this question. We also answer the analogous question for other del Pezzo surfaces, and consider the inverse Galois problem for del Pezzo surfaces over finite fields. Finally we give a corrected version of Manin's and Swinnerton–Dyer's tables on cubic surfaces over finite fields.

AB - Let S be a smooth cubic surface over a finite field q. It is known that #S( q) = 1 + aq + q2 for some a ∈ {−2, −1, 0, 1, 2, 3, 4, 5, 7}. Serre has asked which values of a can arise for a given q. Building on special cases treated by Swinnerton–Dyer, we give a complete answer to this question. We also answer the analogous question for other del Pezzo surfaces, and consider the inverse Galois problem for del Pezzo surfaces over finite fields. Finally we give a corrected version of Manin's and Swinnerton–Dyer's tables on cubic surfaces over finite fields.

U2 - 10.1017/S0305004118000166

DO - 10.1017/S0305004118000166

M3 - Article

SN - 0305-0041

JO - Mathematical Proceedings of the Cambridge Philosophical Society

JF - Mathematical Proceedings of the Cambridge Philosophical Society

ER -