Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4597238 | Journal of Pure and Applied Algebra | 2010 | 22 Pages |
Abstract
A lot of good properties of étale cohomology only hold for torsion coefficients. We use ultraproducts respectively enlargement construction to define a cohomology theory that inherits the important properties of étale cohomology while allowing greater flexibility with the coefficients. In particular, choosing coefficients âZ/PâZ (for P an infinite prime and âZ the enlargement of Z) gives a Weil cohomology, and choosing âZ/lhâZ (for l a finite prime and h an infinite number) allows comparison with ordinary l-adic cohomology. More generally, for every NââZ, we get a category of âZ/NâZ-constructible sheaves with good properties.
Related Topics
Physical Sciences and Engineering
Mathematics
Algebra and Number Theory
Authors
Lars Brünjes, Christian Serpé,