Robinson forcing and the quasidiagonality problem
  We introduce weakenings of two of the more prominent open problems in the classification of $\mathrm{C}^*$-algebras, namely the quasidiagonality problem and the UCT problem. We show that the a positive solution of the conjunction of the two weaker problems implies a positive solution of the original quasidiagonality problem as well as allows us to give a local, finitary criteria for the MF problem, which asks whether every stably finite $\mathrm{C}^*$-algebra is MF. 
Isaac Goldbring and Thomas Sinclair
math.OA math.LO