2 papers
math.NT2026
The constructive inverse Galois problem via Hilbert modular forms: realizing the transitive group 17T7
Raymond van Bommel, Edgar Costa, Noam D. Elkies +3
We show how Hilbert modular forms can be used in the constructive inverse Galois problem over the rationals. In particular, we prove that the transitive permutation group 17T7, iso…
math.NT2025
Explicit modularity of K3 surfaces with complex multiplication of large degree
Edgar Costa, Andreas-Stephan Elsenhans, Jörg Jahnel +1
We consider the transcendental motive of three K3 surfaces conjectured to have complex multiplication (CM). Under this assumption, we match these to explicit algebraic Hecke qu…