Characterization of compactness of the commutators of bilinear   fractional integral operators
  The compactness of the commutators of bilinear fractional integral operators and point-wise multiplication, acting on products of Lebesgue spaces, is characterized in terms of appropriate mean oscillation properties of their symbols. The compactness of the commutators when acting on product of weighted Lebesgue spaces is also studied. 
Lucas Chaffee, Rodolfo H. Torres
math.FA