English

Localization problems of Quillen

K-Theory and Homology 2024-10-10 v3 Commutative Algebra Algebraic Geometry

Abstract

Let XX be a quasi projective scheme over a noetherian affine scheme Spec(A)Spec(A), UXU\subseteq X be an open subset, and Z=XUZ=X-U.Assume that ZZ is complete intersection, with k=codimZk=codim Z. Consider the map q:K(V(X))K(V(U)) q:{\mathbb K}\left({\mathscr V}(X)\right) \rightarrow {\mathbb K}\left({\mathscr V}(U)\right) of the K{\mathbb K}-theory spectra. We give a description of the homotopy fiber of qq. Let CMZ(X)C{\mathbb M}^Z\left(X\right) denote the full subcategory of perfect modules FCoh(X){\mathscr F} \in Coh(X) such that(1) FU=0{\mathscr F} _{|U}=0, (2) grade(F)=dimV(X)F=kgrade({\mathscr F} )=\dim_{{\mathscr V}(X)}{\mathscr F}=k . It turns out that the homotopy fiber of qq is the K{\mathbb K}-theory spectra K(CMZ(X)){\mathbb K}\left(C{\mathbb M}^Z\left(X\right)\right). Likewise, we compute the homotopy fiber of the pullback map g:GW(V(X))GW(V(U)) g: {\mathbb G}W\left({\mathscr V}(X)\right) \rightarrow {\mathbb G}W\left({\mathscr V}(U)\right) of Karoubi Grothendieck-Witt bispectra. Consequently, we obtain long exact sequences of K{\mathbb K}-groups and of GW{\mathbb G}W-groups. These results settle some of the long standing open problems. We also inserted a conjecture.

Keywords

Cite

@article{arxiv.2306.09284,
  title  = {Localization problems of Quillen},
  author = {Satya Mandal},
  journal= {arXiv preprint arXiv:2306.09284},
  year   = {2024}
}

Comments

Corrected, edited, inserted a conjecture

R2 v1 2026-06-28T11:06:13.070Z