Coalgebraic $K$-theory

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gerhardt, Teena, Péroux, Maximilien, Soré, W. Hermann B.
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915947933073408
author Gerhardt, Teena
Péroux, Maximilien
Soré, W. Hermann B.
author_facet Gerhardt, Teena
Péroux, Maximilien
Soré, W. Hermann B.
contents We establish comparison maps between the classical algebraic $K$-theory of algebras over a field and its analogue $K^c$, an algebraic $K$-theory for coalgebras over a field. The comparison maps are compatible with the Hattori--Stallings (co)traces. We identify conditions on the algebras or coalgebras under which the comparison maps are equivalences. Notably, the algebraic $K$-theory of the power series ring is equivalent to the $K^c$-theory of the divided power coalgebra. We also establish comparison maps between the $G$-theory of finite dimensional representations of an algebra and its analogue $G^c$ for coalgebras. In particular, we show that the Swan theory of a group is equivalent to the $G^c$-theory of the representative functions coalgebra, reframing the classical character of a group as a trace in coHochschild homology.
format Preprint
id arxiv_https___arxiv_org_abs_2503_04897
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Coalgebraic $K$-theory
Gerhardt, Teena
Péroux, Maximilien
Soré, W. Hermann B.
K-Theory and Homology
Algebraic Topology
Primary: 16T15, 19D50. Secondary: 18M05, 55U30
We establish comparison maps between the classical algebraic $K$-theory of algebras over a field and its analogue $K^c$, an algebraic $K$-theory for coalgebras over a field. The comparison maps are compatible with the Hattori--Stallings (co)traces. We identify conditions on the algebras or coalgebras under which the comparison maps are equivalences. Notably, the algebraic $K$-theory of the power series ring is equivalent to the $K^c$-theory of the divided power coalgebra. We also establish comparison maps between the $G$-theory of finite dimensional representations of an algebra and its analogue $G^c$ for coalgebras. In particular, we show that the Swan theory of a group is equivalent to the $G^c$-theory of the representative functions coalgebra, reframing the classical character of a group as a trace in coHochschild homology.
title Coalgebraic $K$-theory
topic K-Theory and Homology
Algebraic Topology
Primary: 16T15, 19D50. Secondary: 18M05, 55U30
url https://arxiv.org/abs/2503.04897