Stone's representation theorem for Boolean algebras

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In

operators on a Hilbert space
.

Stone spaces

Each

basis
consisting of all sets of the form where b is an element of B. These sets are also
of homomorphisms into the two-element Boolean algebra.

For every Boolean algebra B, S(B) is a

; such spaces are called Stone spaces (also profinite spaces). Conversely, given any topological space X, the collection of subsets of X that are clopen is a Boolean algebra.

Representation theorem

A simple version of Stone's representation theorem states that every Boolean algebra B is isomorphic to the algebra of clopen subsets of its Stone space S(B). The isomorphism sends an element to the set of all ultrafilters that contain b. This is a clopen set because of the choice of topology on S(B) and because B is a Boolean algebra.

Restating the theorem using the language of

equivalence
between the categories. This was an early example of a nontrivial duality of categories.

The theorem is a special case of Stone duality, a more general framework for dualities between topological spaces and partially ordered sets.

The proof requires either the axiom of choice or a weakened form of it. Specifically, the theorem is equivalent to the Boolean prime ideal theorem, a weakened choice principle that states that every Boolean algebra has a prime ideal.

An extension of the classical Stone duality to the category of Boolean spaces (that is,

locally compact Hausdorff spaces) and continuous maps (respectively, perfect maps) was obtained by G. D. Dimov (respectively, by H. P. Doctor).[2][3]

See also

Citations

References