Non-hyperelliptic Riemann surfaces with real field of moduli but not definable over the reals

摘要

The known examples of explicit equations for Riemann surfaces whose field of moduli is different from their field of definition, are all hyperelliptic. In this paper we construct a family of equations for non-hyperelliptic Riemann surfaces, each of them is isomorphic to its conjugate Riemann surface, but none of them admit an anticonformal automorphism of order 2; that is, each of them has its field of moduli, but not a field of definition, contained in mathbb R{{mathbb R}} . These appear to be the first explicit such examples in the non-hyperelliptic case.