English

A bivariant Yoneda lemma and $(\infty,2)$-categories of correspondences

Category Theory 2022-12-21 v2 Algebraic Topology K-Theory and Homology

Abstract

Everyone knows that if you have a bivariant homology theory satisfying a base change formula, you get an representation of a category of correspondences. For theories in which the covariant and contravariant transfer maps are in mutual adjunction, these data are actually equivalent. In other words, a 2-category of correspondences is the universal way to attach to a given 1-category a set of right adjoints that satisfy a base change formula. Through a bivariant version of the Yoneda paradigm, I give a definition of correspondences in higher category theory and prove an extension theorem for bivariant functors. Moreover, conditioned on the existence of a 2-dimensional Grothendieck construction, I provide a proof of the aforementioned universal property. The methods, morally speaking, employ the `internal logic' of higher category theory: they make no explicit use of any particular model.

Keywords

Cite

@article{arxiv.2005.10496,
  title  = {A bivariant Yoneda lemma and $(\infty,2)$-categories of correspondences},
  author = {Andrew W. Macpherson},
  journal= {arXiv preprint arXiv:2005.10496},
  year   = {2022}
}

Comments

62 pages. Final version. To appear in Algebraic Geom. Topol.. Keywords: bivariant homology, correspondences, spans, (infinity,2)-category, Yoneda, Beck-Chevalley, base change, straightening, Grothendieck construction, biCartesian fibration