English

One-motives and a conjecture of Deligne

Algebraic Geometry 2015-06-29 v3 Number Theory

Abstract

We introduce new motivic invariants of arbitrary varieties over a perfect field. These cohomological invariants take values in the category of one-motives (considered up to isogeny in positive characteristic). The algebraic definition of these invariants presented here proves a conjecture of Deligne. Applications include some cases of conjectures of Serre, Katz and Jannsen on the independence of \ell of parts of the \'etale cohomology of arbitrary varieties over number fields and finite fields.

Keywords

Cite

@article{arxiv.math/9806117,
  title  = {One-motives and a conjecture of Deligne},
  author = {Niranjan Ramachandran},
  journal= {arXiv preprint arXiv:math/9806117},
  year   = {2015}
}

Comments

43 pages, latex file, uses amsart, amscd packages (Major revisions; final version). Journal of Algebraic Geometry (to appear)