Published online by Cambridge University Press: 07 May 2019
We give a bound on the primes dividing the denominators of invariants of Picard curves of genus 3 with complex multiplication. Unlike earlier bounds in genus 2 and 3, our bound is based, not on bad reduction of curves, but on a very explicit type of good reduction. This approach simultaneously yields a simplification of the proof and much sharper bounds. In fact, unlike all previous bounds for genus 3, our bound is sharp enough for use in explicit constructions of Picard curves.
Author E. L. G. was partially supported by a project PEPS-Jeunes Chercheur-e-s - 2017. Author P. K. was partially supported by DFG priority project SPP 1489.