Units of equivariant ring spectra
arXiv:0912.4346 · doi:10.2140/agt.2011.11.1361
Abstract
It is well known that very special -spaces and grouplike $\E_\infty$ spaces both model connective spectra. Both these models have equivariant analogues. Shimakawa defined the category of equivariant -spaces and showed that special equivariant -spaces determine positive equivariant spectra. Costenoble and Waner showed that grouplike equivariant $\E_\infty$-spaces determine connective equivariant spectra. We show that with suitable model category structures the category of equivariant -spaces is Quillen equivalent to the category of equivariant $\E_\infty$ spaces. We define the units of equivariant ring spectra in terms of equivariant -spaces and show that the units of an equivariant ring spectrum determines a connective equivariant spectrum.
More detailed introduction, added appendix C