English

On the weight zero motivic cohomology

Algebraic Geometry 2024-11-28 v1

Abstract

We prove that singular cohomology of the underlying space of Berkovich's analytification of a scheme XX locally of finite type over a trivially-valued field kk of characteristic 00 is isomorphic to cdh-cohomology with integer coefficients which is also isomorphic to the weight zero motivic cohomology H(X,Z)H^*(X, \mathbb{Z}). Using this isomorphism, we demonstrate the vanishing of RHomShNis(cork)(G,Z)RHom_{Sh_{Nis}(cor_k)}(\underline{G},\mathbb{Z}), where G\underline{G} denotes the Nisnevich sheaf with transfers associated with a commutative algebraic group GG over kk. For abelian kk-varieties AA and BB, we prove that RHomPShtr(A,B)RHom_{\mathcal{PS}h_{tr}}(\underline{A},\underline{B}) is isomorphic to HomAbk(A,B)Hom_{\mathbf{Ab_k}}(A,B).

Keywords

Cite

@article{arxiv.2411.18274,
  title  = {On the weight zero motivic cohomology},
  author = {Semen Molokov and Vadim Vologodsky},
  journal= {arXiv preprint arXiv:2411.18274},
  year   = {2024}
}

Comments

27 pages, comments welcome