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Related papers: Jump of Milnor numbers

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The jump of the Milnor number of an isolated singularity $f_0$ is the minimal non-zero difference between the Milnor numbers of $f_0$ and one of its deformations $(f_s)$. We give a formula for the jump in some class of surface singularities…

Algebraic Geometry · Mathematics 2016-10-25 Szymon Brzostowski , Tadeusz Krasiński , Justyna Walewska

The jump of the Milnor number of an isolated singularity $f_0$ is the minimal non-zero difference between the Milnor numbers of $f_0$ and one of its deformations $f_s$. We determinate the jump of quasihomogeneous singularities in the class…

Algebraic Geometry · Mathematics 2023-12-01 Aleksandra Zakrzewska

The jump of the Milnor number of an isolated singularity $f_0$ is the minimal non-zero difference between the Milnor numbers of $f_0$ and one of its deformations $(f_s)).$ We prove that for the singularities in the $X_9$ singularity class…

Algebraic Geometry · Mathematics 2013-01-08 Szymon Brzostowski , Tadeusz Krasinski

Let f_0 be a plane curve singularity. We study the Minor numbers of singularities in deformations of f_0. We completely describe the set of these Milnor numbers for homogeneous singularities f_0 in the case of non-degenerate deformations…

Algebraic Geometry · Mathematics 2016-11-17 Szymon Brzostowski , Tadeusz Krasinski , Justyna Walewska

The jump of the Milnor number of an isolated singularity $f_{0}$ is the minimal non-zero difference between the Milnor numbers of $f_{0}$ and one of its deformation $(f_{s}).$ In the case $f_{s}$ are non-degenerate singularities we call the…

Algebraic Geometry · Mathematics 2018-03-15 Tadeusz Krasiński , Justyna Walewska

The aim of this paper is to show the possible Milnor numbers of deformations of semi-quasi-homogeneous isolated plane curve singularities. Main result states that if $f$ is irreducible and nondegenerate, by deforming $f$ one can attain all…

Algebraic Geometry · Mathematics 2014-09-24 Maria Michalska , Justyna Walewska

We show the possible Milnor numbers of deformations of semi-quasi-homogeneous isolated plane curve singularities. In Theorem 1.1 we list integers can be attained as Milnor numbers of a given semi-quasi-homogeneous singularity.

Algebraic Geometry · Mathematics 2016-08-15 Maria Michalska , Justyna Walewska

In this survey we overview the different approaches and solutions of a question posed by Dimca and Greuel about the quotient of the Milnor and Tjurina numbers.

Algebraic Geometry · Mathematics 2020-06-03 Patricio Almirón

In this paper we give a positive answer to a question of Dimca and Greuel about the quotient between the Milnor and the Tjurina numbers for any irreducible germ of plane curve singularity. This result is based on a closed formula for the…

Algebraic Geometry · Mathematics 2020-01-08 Maria Alberich-Carramiñana , Patricio Almirón , Guillem Blanco , Alejandro Melle-Hernández

We deal with the following closely related problems: (i) For a germ of a reduced plane analytic curve, what is the minimal degree of an algebraic curve with a singular point analytically equivalent (isomorphic) to the given one? (ii) For a…

Algebraic Geometry · Mathematics 2007-05-23 Eugenii Shustin

Let $f=0$ be a plane algebraic curve of degree $d>1$ with an isolated singular point at the origin of the complex plane. We show that the Milnor number $\mu_0(f)$ is less than or equal to $(d-1)^2-\left[\frac{d}{2}\right]$, unless $f=0$ is…

Algebraic Geometry · Mathematics 2013-05-23 Arkadiusz Płoski

We study deformations of holomorphic function germs $f:(X,0)\to\mathbb C$ where $(X,0)$ is an ICIS. We present conditions for these deformations to have constant Milnor number, Euler obstruction and Bruce-Roberts number.

Algebraic Geometry · Mathematics 2018-07-03 R. S. Carvalho , B. Orefice-Okamoto , J. N. Tomazella

Jump deformations and contractions of Lie algebras are inverse concepts, but the approaches to their computations are quite different. In this paper, we contrast the two approaches, showing how to compute jump deformations from the…

Quantum Algebra · Mathematics 2009-11-13 Alice Fialowski , Michael Penkava

We collect some classical results about holomorphic 1-forms of a reduced complex curve singularity, in particular of a complete intersection, and use them to compare the Milnor number, the Tjurina number and the dimension of the torsion…

Algebraic Geometry · Mathematics 2017-09-12 Gert-Martin Greuel

In this paper we give a complete answer to a question posed by Dimca and Greuel about the quotient of the Milnor and Tjurina numbers of a plane curve singularity. We put this question into a general framework of the study of the difference…

Algebraic Geometry · Mathematics 2021-09-13 Patricio Almirón

We prove a lower bound for the Milnor number of function germ invariant with respect to a finite abelian group action. It is shown that this bound is tight for functions of arbitrarily many variables. We also prove the function germs that…

Algebraic Geometry · Mathematics 2026-01-14 Ivan Proskurnin

Many classical results in algebraic geometry arise from investigating some extremal behaviors that appear among projective varieties not lying on any hypersurface of fixed degree. We study two numerical invariants attached to such…

Algebraic Geometry · Mathematics 2019-06-20 Edoardo Ballico , Emanuele Ventura

We introduce the concept of good Saito's basis for a plane curve $S$ and we explore it to obtain a formula for the minimal Tjurina number in a topological class. In particular, we present a positive answer for a question of Dimca and Greuel…

Algebraic Geometry · Mathematics 2019-04-26 Marcelo E. Hernandes , Yohann Genzmer

We describe a new algebro-geometric perspective on the study of the Milnor fibration and, as a first step toward putting it into practice, prove powerful criteria for a deformation of a holomorphic function germ to admit a stratification on…

Algebraic Geometry · Mathematics 2025-03-04 Alex Hof

We study functions on isolated singularities and prove some results of type Milnor number = Tjurina number. We use them to endow the base space of their miniversal deformation with the structure of F-manifold.

Algebraic Geometry · Mathematics 2007-05-23 Ignacio de Gregorio
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