A sharp height estimate for compact hypersurfaces with constant $k$-mean   curvature in warped product spaces
  In this paper we obtain a sharp height estimate concerning compact hypersurfaces immersed into warped product spaces with some constant higher order mean curvature, and whose boundary is contained into a slice. We apply these results to draw topological conclusions at the end of the paper. 
Sandra C. Garc\'ia-Mart\'inez, Debora Impera and Marco Rigoli
math.DG