Algebraic part of motivic cohomology with compact supports

Abstract

Motivated by Murre's work on universal regular homomorphisms on Chow groups in codimension $2,$ we generalize the algebraic equivalence relation and regular homomorphisms to the context of Voevodsky motives over a field. In the Nisnevich topology, we prove the existence of \emph{universal} regular homomorphisms for a certain class of motivic cohomology groups, recovering Murre's theorem and the existence of Picard and Albanese varieties as special cases. This class also includes interesting cases such as higher Chow groups and Milnor $K$-groups. The appendix by Kahn proves that, for \'etale motives, universal regular homomorphisms exist for all geometric motives and compares them with those in the Nisnevich topology when both exist.