2015/09/01 by Paskunas, Vytautas
#FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.1509.00320
We compute the versal deformation ring of a split generic 2-dimensional representation χ1⊕ χ2 of the absolute Galois group of ℚp. As an application, we show that the Breuil--Mézard conjecture for both non-split extensions of χ1 by χ2 and χ2 by χ1 implies the Breuil--Mézard conjecture for χ1⊕ χ2. The result is new for p=2, the proof works for all primes.