Generalized polar varieties and an efficient real elimination
Let be a closed algebraic subvariety of the -dimensional projective space over the complex or real numbers and suppose that is non-empty and equidimensional. In this paper we generalize the classic notion of polar variety of associated with a given linear subvariety of the ambient space of . As particular instances of this new notion of generalized polar variety we reobtain the classic ones and two new types of polar varieties, called dual and (in case that is affine) conic. We show that...