(Hampton University/Jefferson Lab)
It has been recently proposed that PDFs can be studied directly using lattice QCD. Such studies require the evaluation of matrix of non-local operators. Since this was first proposed, there has been an intense investigation of all possible systematics except for the effects associated with the fact that lattice QCD is necessarily defined in a finite spacetime. In this talk, I present the first attempt to assess these systematics, and I show that these matrix elements might suffer of large finite-volume artifacts.