English

Homotopy structures realizing algebraic kk-theory

K-Theory and Homology 2025-12-10 v3 Category Theory

Abstract

Algebraic kkkk-theory, introduced by Corti\~nas and Thom, is a bivariant KK-theory defined on the category Alg\mathrm{Alg} of algebras over a commutative unital ring \ell. It consists of a triangulated category kkkk endowed with a functor from Alg\mathrm{Alg} to kkkk that is the universal excisive, homotopy invariant and matrix-stable homology theory. Moreover, one can recover Weibel's homotopy KK-theory KH\mathrm{KH} from kkkk since we have kk(,A)=KH(A)kk(\ell,A)=\mathrm{KH}(A) for any algebra AA. We prove that Alg\mathrm{Alg} with the split surjections as fibrations and the kkkk-equivalences as weak equivalences is a stable category of fibrant objects, whose homotopy category is kkkk. As a consecuence of this, we prove that the Dwyer-Kan localization kkkk_\infty of the \infty-category of algebras at the set of kkkk-equivalences is a stable infinity category whose homotopy category is kkkk.

Keywords

Cite

@article{arxiv.2412.19936,
  title  = {Homotopy structures realizing algebraic kk-theory},
  author = {Eugenia Ellis and Emanuel Rodríguez Cirone},
  journal= {arXiv preprint arXiv:2412.19936},
  year   = {2025}
}

Comments

Some typos were corrected and Appendix B was dropped. Version to appear in Orbita Mathematicae. 40 pages

R2 v1 2026-06-28T20:50:20.316Z