Classification of Track (Bi)Categories via Group-Valued 3-Cocycles
摘要
Track bicategories, where each hom-category is a groupoid, appear in various mathematical and physical contexts. In this paper, we establish a cohomological classification of track bicategories and track categories using group-valued 3-cocycles on small categories, formulated as lax functors into the one-object 3-category of groups. In the abelian case, this classification aligns with Baues-Wirsching cohomology for small categories with coefficients in natural systems, recovering previously known classification results.