DOI: 10.1002/mana.70292 ISSN: 0025-584X
Unexpected Primes of Good Reduction in Quotients of Modular and Shimura Curves
Oana Padurariu, Sun Woo Park, John VoightABSTRACT
We find all zero‐dimensional spaces of newforms of weight 2 and squarefree level with a fixed Atkin–Lehner sign pattern. As an application, we classify unexpected primes of good reduction of Atkin–Lehner quotients of modular and Shimura curves of squarefree levels.