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Related papers: On irreducible germs of generic morphisms

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Let $M$ be a smooth surface in $\mathbb R^3$ (or a complex surface in $\mathbb C^3$) and $k\geq 2$ be an integer. At any point on $M$ and for any plane in $\mathbb R^3$, we construct a holomorphic map-germ $(\mathbb C^2,0)\to(\mathbb…

Differential Geometry · Mathematics 2021-02-15 G. Peñafort Sanchis , F. Tari

In this paper we prove that the branch curve of a general projection of a surface to the plane is irreducible, with only nodes and cusps.

Algebraic Geometry · Mathematics 2010-06-17 Ciro Ciliberto , Flaminio Flamini

Let $\mathcal{X}$ be an irreducible algebraic curve defined over a finite field $\mathbb{F}_q$ of characteristic $p>2$. Assume that the $\mathbb{F}_q$-automorphism group of $\mathcal{X}$ admits as an automorphism group the direct product of…

Algebraic Geometry · Mathematics 2016-08-16 Nazar Arakelian , Pietro Speziali

The paper is devoted to relations between topological and metric properties of germs of real surfaces, obtained by analytic maps from $R^2$ to $R^4$. We show that for a big class of such surfaces the normal embedding property implies the…

Algebraic Geometry · Mathematics 2018-01-19 Lev Birbrair , Rodrigo Mendes , Juan Jose Nuño-Ballesteros

Let $V$ be a left vector space over a division ring and let ${\mathcal P}(V)$ be the associated projective space. We describe all finite subsets $X\subset V$ such that every permutation on $X$ can be extended to a linear automorphism of $V$…

Group Theory · Mathematics 2012-06-28 Mark Pankov

In 1982, Tamaki Yano proposed a conjecture predicting the set of b-exponents of an irreducible plane curve singularity germ which is generic in its equisingularity class. In \cite{ACLM-Yano2} we proved the conjecture for the case in which…

Algebraic Geometry · Mathematics 2016-11-04 E. Artal Bartolo , Pi. Cassou-Noguès , I. Luengo , A. Melle-Hernández

In this paper we expand on previous results, studying the extent to which one can detect fusion in certain finite groups $\Gamma$, from information about the universal deformation rings of absolutely irreducible…

Rings and Algebras · Mathematics 2016-02-10 David C. Meyer

Let $F$ be a local field of characteristic $p$ and $G$ be a connected reductive group over $F$. Recall that Shalika's germ expansion of orbital integrals of regular semi-simple elements near the identity, when it exists, is a sum indexed by…

Representation Theory · Mathematics 2025-07-23 Jean-Pierre Labesse

Let $G$ be the unramified unitary group $U(2, 1)(E/F)$ defined over a non-archimedean local field $F$ of odd residue characteristic $p$, and $B$ be the standard Borel subgroup of $G$. In this note, we study the problem of the restriction of…

Representation Theory · Mathematics 2025-03-25 Peng Xu

The decomposition of a two dimensional complex germ with non-isolated singularity into semi-algebraic sets is given. This decomposition consists of four classes: Riemannian cones defined over a Seifert fibered manifold, a topological cone…

Algebraic Geometry · Mathematics 2014-11-14 Noémie Combe

We study corank one $A$-finite germs $f:(\mathbb{R}^n,0)\rightarrow (\mathbb{R}^{n+1},0)$ and their complexifications. More precisely, we study when these germs provide good real pictures of the complex germs, i.e., when there is a real…

Algebraic Geometry · Mathematics 2025-07-21 R. Giménez Conejero , Ignacio Breva Ribes

An element $g$ of a group is called {\em reversible} if it is conjugate in the group to its inverse. This paper is about reversibles in the group $G$ of formally-invertible pairs of formal power series in two variables, with complex…

Complex Variables · Mathematics 2022-03-22 Anthony G. O'Farrell , Dmitri Zaitsev

We look at topological equisingularity of a holomorphic family of reduced mapping germs f_t:(C^3,O)->C over a contractible base T having non-isolated singularities, by means of their normalisations. We introduce the notion of…

Algebraic Geometry · Mathematics 2007-05-23 Javier Fernandez de Bobadilla , Maria Pe Pereira

We classify generic unfoldings of germs of antiholomorphic diffeomorphisms with a parabolic point of codimension~$k$ (i.e.~a fixed point of multiplicity $k+1$) under conjugacy. Such generic unfoldings depend real analytically on $k$ real…

Dynamical Systems · Mathematics 2023-01-30 Christiane Rousseau

This work concerns the problem of relating characteristic numbers of one-dimensional holomorphic foliations of P^n to those of algebraic varieties invariant by them. More precisely: if M is a connected complex manifold, a one-dimensional…

Complex Variables · Mathematics 2016-09-07 Marcio G. Soares

We provide a family of isolated tangent to the identity germs $f:(\mathbb{C}^3,0) \to (\mathbb{C}^3,0)$ which possess only degenerate characteristic directions, and for which the lift of $f$ to any modification (with suitable properties)…

Dynamical Systems · Mathematics 2021-08-03 Samuele Mongodi , Matteo Ruggiero

Let f = 0 be an implicit singular plane curve. When deforming f = 0, inflections and vertex emerge from the singularities. In this papper, we classify the deformations of f = 0 with respect to the inflections and the vertices in the cases…

Differential Geometry · Mathematics 2025-02-28 Marco Antônio do Couto Fernandes , Samuel Paulino dos Santos

Suppose $\phi$ is a wildly ramified cover of germs of curves defined over an algebraically closed field of characteristic p. We study unobstructed deformations of $\phi$ in equal characteristic, which are equiramified in that the branch…

Algebraic Geometry · Mathematics 2007-05-23 Rachel Pries

We explore the existence of irreducible and reducible arc-sections in an irreducible hypersurface singularity germ along finite projections. In particular we provide examples of irreducible isolated hypersurface singularities for which no…

Algebraic Geometry · Mathematics 2019-04-02 Miguel Angel Marco-Buzunariz , Maria Pe Pereira

Let $S$ be a closed Riemann surface of genus $g \geq 2$ and $\varphi$ be a conformal automorphism of $S$, of prime order $p$ such that $S/\langle \varphi \rangle$ has genus zero. Let ${\mathbb K} \leq {\mathbb C}$ be a field of definition…

Algebraic Geometry · Mathematics 2021-02-25 Ruben A. Hidalgo