Number Theory Commons^™

Obstruction Criteria For Modular Deformation Problems, Jeffrey Hatley Jr

Doctoral Dissertations

For a cuspidal newform f of weight k at least 3 and a prime p of the associated number field K_f, the deformation problem for its associated mod p Galois representation is unobstructed for all primes outside some finite set. Previous results gave an explicit bound on this finite set for f of squarefree level; we modify this bound and remove the squarefree hypothesis. We also show that if the p-adic deformation problem for f is unobstructed, then f is not congruent mod p to a newform of lower level.