Cohomology with coefficients in stacks of Picard categories
  Cohomology of a topological space with coefficients in stacks of abelian 2-groups is considered. A 2-categorical analog of the theorem of Grothendieck is proved, relating cohomology of the space with coefficients in a 2-stage spectrum and the Ext groups of appropriate stacks. 
Mamuka Jibladze and Teimuraz Pirashvili
math.AT math.AG