H. Santana

activity

20192026

collaborators

6 papers

math.GT2026

Poincaré-Hopf Theorem for Isolated Determinantal Singularities

N. G. Grulha, M. S. Pereira, H. Santana

Let $X$ be a projective algebraic $d$ -variety endowed with isolated determinantal singularities, and let $ω$ be a $1$ -form on $X$ exhibiting a finite number of singularities (in th…

math.GT2020

The geometrical information encoded by the Euler obstruction of a map

Nivaldo G. Grulha, Camila Ruiz, Hellen Santana

In this work we investigate the topological information captured by the Euler obstruction of a map, $f : (X, 0) \to (C^{2}, 0)$ , with $(X, 0)$ a germ of a complex $d$ -equidimens…

math.GT2020

About relative polar varieties and Brasselet numbers

Hellen Santana

In this work, we study the consequences of an empty polar variety on the topology of a function-germ with (possibly) nonisolated singularities defined on a singular variety.

math.GT2020

Poincaré-Hopf Theorem for Isolated Determinantal Singularities

N. G. Grulha, M. S. Pereira, H. Santana

Let $X \subset P^{r}$ be a projective $d$ -variety with isolated determinantal singularities and $ω$ be a $1$ -form on $X$ with a finite number of singularities (in the stratif…

math.GT2019

Local topology of a deformation of a function-germ with a one-dimensional critical set

Hellen Santana

The Brasselet number of a function $f$ with nonisolated singularities describes numerically the topological information of its generalized Milnor fibre. In this work, we consider t…

math.GT2019

Brasselet number and function-germs with a one-dimensional critical set

Hellen Santana

The Brasselet number of a function $f$ with nonisolated singularities describes numerically the topological information of its generalized Milnor fibre. In this work, using the Bra…