Thomason cohomology of categories
  We introduce cohomology and homology theories for small categories with general coefficient systems from simplex categories first studied by Thomason. These theories generalize at once Baues-Wirsching cohomology and homology and other more classical theories. We analyze naturality and functoriality properties of these theories and construct associated spectral sequences for functors between small categories. 
Imma Galvez-Carrillo, Frank Neumann, Andrew Tonks
math.KT math.AT math.CT