Categories (Mathematics) Functor theory 6 Homology theory 5 Topology 5 Toposes 5 Homotopy theory 4 Sheaf theory 4 Algebraic spaces 2 Complexes 2 Geometry, Algebraic 2 K-theory 2 Logic, Symbolic and mathematical 2 Loop spaces 2 Modules (Algebra) 2 Abelian varieties 1 Algebra, Abstract 1 Algebra, Homological 1 Algebra, Universal 1 Arithmetical algebraic geometry 1 Associative algebras 1 Associative rings 1 Banach spaces 1 C*-algebras 1 Class field theory 1 Commutative algebra 1 Commutative rings 1 Continuous lattices 1 Duality theory (Mathematics) 1 Fiber bundles (Mathematics) 1 Formal groups 1