Analysis MOC

Stone-Weierstraß theorem

Let be a compact space and be a ∗-subalgebra of the continuous function ∗-algebra that is separating. Then is dense in , #m/thm/anal/fun i.e. .

Proof

#missing/proof

Finite version

Let be a subalgebra of the function algebra on a finite set . Then iff separates points, #m/thm/linalg i.e. for any distinct there exists so that and

Proof

Assume is separating. For each , let so that 1. Defining as above, it follows

and since span it follows . For the converse just set for all .


#state/develop | #lang/en | #SemBr

Footnotes

  1. Invoking an Iverson bracket.