Abstract
For a not-necessarily commutative ring R we define an abelian group W(R;M) of Witt vectors with coefficients in an R-bimodule M. These groups generalize the usual big Witt vectors of commutative rings and we prove that they have analogous formal properties and structure. One main result is that W(R) ∶= W(R;R) is Morita invariant in R. For an R-linear endomorphism f of a finitely generated projective R-module we define a characteristic element χf ∈ W(R). This element is a non-commutative analogue of the classical characteristic polynomial and we show that it has similar properties. The assignment f ↦ χf induces an isomorphism between a suitable completion of cyclic K-theory K cyc0 (R) and W(R).
Original language | English |
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Pages (from-to) | 366-408 |
Number of pages | 43 |
Journal | Compositio Mathematica |
Volume | 158 |
Issue number | 2 |
Early online date | 26 Apr 2022 |
DOIs | |
Publication status | Published - 26 Apr 2022 |
Bibliographical note
Funding Information:The first and the fourth authors were supported by the German Research Foundation Schwerpunktprogramm 1786 and by the Hausdorff Center for Mathematics at the University of Bonn. The second and third authors were funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy EXC 2044 390685587, Mathematics Münster: Dynamics–Geometry–Structure.
Keywords
- Witt vectors
- characteristic polynomial
- trace
- TRACE