Equivariant Hirzebruch class for quadratic cones via degenerations
  We compute the equivariant Hirzebruch class of the quadric cone in C^n degenerating it to an intersection to hyperplanes. The difference of the Hirzebruch classes (measured by the Milnor class) turns out to be the Hirzebruch class of the complement of the quadratic cone of smaller dimension. 
Malgorzata Mikosz, Andrzej Weber
math.AG math.AT