arXiv subjects

Robert Gassler

Publications and source records attributed to Robert Gassler.

3 recordsLinked to original sources

arXiv1997

Mixed Segre Numbers and Integral Closure of Ideals

We introduce mixed Segre numbers of ideals which generalize the notion of mixed multiplicities of ideals of finite colength and show how many results on mixed multiplicities can be extended to results on mixed Segre numbers. In particular, we give a necessary and sufficient condition in terms of these numbers for two ideals to have the same integral closure. Also, our theory yields a new proof of a generalization of Rees' theorem that links the integral closure of an ideal to its multiplicity. Finally, we give a quick application of our results to Whitney equisingularity.

alg-geom↗

arXiv1996

Segre Numbers and Hypersurface Singularities

We define the Segre numbers of an ideal as a generalization of the multiplicity of an ideal of finite colength. We prove generalizations of various theorems involving the multiplicity of an ideal such as a principle of specialization of integral dependence, the Rees-Böger theorem, and the formula for the multiplicity of the product of two ideals. These results are applied to the study of various equisingularity conditions, such as Verdier's condition W, and conditions $A_f$ and $W_f$.

alg-geom↗

arXiv1994

Conformal Differential Forms of an Analytic Germ

A differential form vanishing on the tangent space at smooth points of a reduced embedded analytic germ is called conormal. For proving that a conormal one--form of a hypersurface vanishes at its singularities we state a Bertini--type theorem.

alg-geom↗