2008/07/07 by Lars Brünjes, Brünjes, Lars, Christian Serpé +1
Mathematics · #03C20 #14F20 #14F42 #Algebraic Geometry (math.AG) #Algebraic Geometry and Number Theory #Algebraic structures and combinatorial models #FOS: Mathematics #Homotopy and Cohomology in Algebraic Topology #Logic (math.LO) #math.AG #math.LO #msc:03C20 #msc:14F20 #msc:14F42
paper · pdf · doi:10.48550/arxiv.0807.1007
28 pages
arxiv created 2008/07/07 · openalex publication_date 2008/07/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
This paper is a continuation of the authors article "Enlargements of schemes" (Log. Anal.1 (2007), no. 1, 1-60) We mainly study the behaviour of etale cohomology, algebraic cycles and motives under ultraproducts respectively enlargements. The main motivation for that is to find methods to transfer statements about etale cohomology and algebraic cycles from characteristic zero to positive characteristic and vice versa. We give one application to the independence of l of Betti numbers in etale cohomology and applications to the complexity of algebraic cycles.