Functoriality of the coniveau filtration
  There is a natural descending filtration on the singular cohomology of a complex smooth projective variety called the coniveau filtration. The generalized Hodge conjecture would imply, rather trivially, that the coniveau filtration is compatible with pushforwards, pullbacks and products. The purpose of this paper is to prove this statement unconditionally. This completes the argument in math.AG/0102070. 
Donu Arapura, Su-Jeong Kang