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Vanishing theorems for real algebraic cycles
- American Journal of Mathematics
- Johns Hopkins University Press
- Volume 134, Number 3, June 2012
- pp. 649-709
- 10.1353/ajm.2012.0022
- Article
- Additional Information
We establish the analogue of the Friedlander-Mazur conjecture for Teh's reduced Lawson homology groups
of real varieties, which says that the reduced Lawson homology of a real quasi-projective variety $X$
vanishes in homological degrees larger than the dimension of $X$ in all weights. As an application we
obtain a vanishing of homotopy groups of the mod-$2$ topological groups of averaged cycles and a
characterization in a range of indices of dos Santos' real Lawson homology as the homotopy groups of the
topological group of averaged cycles. We also establish an equivariant Poincare duality between
equivariant Friedlander-Walker real morphic cohomology and dos Santos' real Lawson homology.
We use this together with an equivariant extension of the mod-$2$ Beilinson-Lichtenbaum conjecture to
compute some real Lawson homology groups in terms of Bredon cohomology.