Commutative ring spectrum

In the mathematical field of algebraic topology, a commutative ring spectrum, roughly equivalent to a -ring spectrum, is a commutative monoid in a good category of spectra. The category of commutative ring spectra over the field of rational numbers is Quillen equivalent to the category of differential graded algebras over . Example: The Witten genus may be realized as a morphism of commutative ring spectra →tmf. See also: simplicial commutative ring, highly structured ring spectrum and derived scheme. rdf:langString