### Rings, modules, and algebras in infinite loop space theory, by Anthony D. Elmendorf and Michael A. Mandell

We give a new construction of the algebraic K-theory
of small permutative categories that preserves multiplicative
structure, and therefore allows us to give a unified treatment of
rings, modules, and algebras in both the input and output. This
requires us to define multiplicative structure on the category of
small permutative categories. The framework we use is the concept
of multicategory, a generalization of symmetric monoidal category
that precisely captures the multiplicative structure we have
present at all stages of the construction. Our method ends up in
Smith's category of symmetric spectra, with an intermediate stop
at a new category that may be of interest in its own right, whose
objects we call symmetric functors.

Anthony D. Elmendorf <aelmendo@math.purdue.edu>

Michael A. Mandell <mandell@math.uchicago.edu>