Algebras and modules
Model category presentations
Geometry on formal duals of algebras
In an associative algebra , the commutant of a set of elements of is the set
of elements in that commute with all elements in .
The operation of taking a commutant is a contravariant map that is adjoint to itself in the sense of Galois connections. In other words, we have for any two subsets the equivalence
Hence and also .
Revised on July 27, 2011 15:57:10
by Urs Schreiber