Torsion algebraic cycles and étale cobordism, by Gereon Quick

We prove that the classical integral cycle class map from algebraic cycles to étale cohomology factors through a quotient of l-adic étale cobordism over an algebraically closed field of positive characteristic. This shows that there is a strong topological obstruction for cohomology classes to be algebraic and that examples of Atiyah, Hirzebruch and Totaro also work in positive characteristic.

• 0949.bib (237 bytes)
• Cycles.dvi (131876 bytes) [November 27, 2009]
• Cycles.dvi.gz (55151 bytes)
• Cycles.pdf (221845 bytes)
• Cycles.ps.gz (206654 bytes)

Gereon Quick <gquick@math.uni-muenster.de>