In this paper we establish a universal characterization of higher algebraic
–theory in the setting of
small stable –categories.
Specifically, we prove that connective algebraic
–theory is
the universal additive invariant, ie the universal functor with values in spectra
which inverts Morita equivalences, preserves filtered colimits and satisfies
Waldhausen’s additivity theorem. Similarly, we prove that nonconnective algebraic
–theory is
the universal localizing invariant, ie the universal functor that moreover satisfies the
Thomason–Trobaugh–Neeman Localization Theorem.
To prove these results, we construct and study two stable
–categories of
“noncommutative motives”; one associated to additivity and another to localization. In these stable
–categories, Waldhausen’s
–construction
corresponds to the suspension functor and connective and nonconnective algebraic
–theory spectra
become corepresentable by the noncommutative motive of the sphere spectrum. In particular, the
algebraic –theory
of every scheme, stack and ring spectrum can be recovered from these categories
of noncommutative motives. In the case of a connective ring spectrum
, we prove moreover that its
negative –groups are isomorphic
to the negative –groups
of the ordinary ring .
In order to work with these categories of noncommutative motives, we establish
comparison theorems between the category of spectral categories localized at the
Morita equivalences and the category of small idempotent-complete stable
–categories.
We also explain in detail the comparison between the
–categorical version of
Waldhausen –theory
and the classical definition.
As an application of our theory, we obtain a complete
classification of the natural transformations from higher algebraic
–theory to topological
Hochschild homology () and
topological cyclic homology ().
Notably, we obtain an elegant conceptual description of the cyclotomic trace
map.
Department of Mathematics
Massachusetts Institute of Technology
77 Massachusetts Avenue
Cambridge, MA 02139
USA
and
Departamento de Matemática e CMA
FCT-UNL
Quinta da Torre
2929-516 Caparica
Portugal