Elliptic symbols, elliptic operators and Poincar\'e duality on conical   pseudomanifolds
  In a earlier work of Claire Debord and the author, a notion of noncommutative tangent space isdefined for a conical pseudomanifold and the Poincar\'e duality in $K$-theory is proved between this space and the pseudomanifold. The present paper continues this work. We show that an appropriate and natural presentation of the notion of symbols on a manifold generalizes right away to conical pseudomanifolds and that it enables us to interpret the Poincar\'e duality in the singular setting as a principal symbol map. 
Jean-Marie Lescure