On Zariski multiplicity conjecture for quasihomogeneous surfaces with non-isolated singularities

Author:

Otoniel Nogueira da Silva

Keyword:

Mathematics, Algebraic Geometry, Algebraic Geometry (math.AG), Complex Variables (math.CV)

journal:

date:

2023-09-05 16:00:00

Abstract

In this work, we consider an $\mathcal{A}$-finite map germ $f$ from $(\mathbb{C}^2,0)$ to $(\mathbb{C}^3,0)$ of corank $1$. If $f$ is quasihomogeneous then we present a characterization of the fold components of the double point curve $D(f)$. We also present the number of fold and identification components of $D(f)$ in terms of the weights and degrees of $f$. As an application of this result, we consider Zariski multiplicity question for germs of surfaces $(X_1,0)$ and $(X_2,0)$, in $(\mathbb{C}^3,0)$ with $1$-dimensional singular set $(\Sigma(X_i),0)$. We suppose that each $X_i$ is quasihomogeneous, i.e., $X_i$ is given by $F_i=0$ where $F_i$ is a quasihomogeneous holomorphic function. We also suppose that the Euler obstruction of $(X_i,0)$ is equal to $1$ and that $(X_i,0)$ is $\delta_1$-minimal, i.e., the $\delta$-invariant of a generic transversal slice of $(X_i,0)$ is equal to the multiplicity of $(\Sigma(X_i),0)$. With this setting, if $(X_1,0)$ and $(X_2,0)$ are topologically equivalent, then we show that the multiplicity of $(X_1,0)$ is equal to the multiplicity of $(X_2,0)$.

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