Dirac operators in tensor categories and the motive of quaternionic   modular forms
  We define a motive whose realizations afford modular forms (of arbitrary weight) on an indefinite division quaternion algebra. This generalizes work of Iovita--Spiess to odd weights in the spirit of Jordan--Livn\'e. It also generalizes a construction of Scholl to indefinite division quaternion algebras. 
Marc Masdeu and Marco Adamo Seveso
math.NT