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Related papers: Oka's conjecture on irreducible plane sextics

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We complete the proof of Oka's conjecture on the Alexander polynomial of an irreducible plane sextic. We also calculate the fundamental groups of irreducible sextics with a singular point adjacent to $J_{10}$.

Algebraic Geometry · Mathematics 2014-02-26 Alex Degtyarev

We compute the fundamental group of the complement of each irreducible sextic of weight eight or nine (in a sense, the largest groups for irreducible sextics), as well as of 169 of their derivatives (both of and not of torus type). We also…

Algebraic Geometry · Mathematics 2010-01-25 Alex Degtyarev

We compute the fundamental groups of all irreducible plane sextics constituting classical Zariski pairs

Algebraic Geometry · Mathematics 2011-02-17 Alex Degtyarev

We complete the equisingular deformation classification of irreducible singular plane sextic curves. As a by-product, we also compute the fundamental groups of the complement of all but a few maximizing sextics.

Algebraic Geometry · Mathematics 2016-09-07 Ayşegül Akyol , Alex Degtyarev

The existence of Alexander-equivalent Zariski pairs dealing with irreducible curves of degree 6 was proved by A. Degtyarev. However, up to now, no explicit example of such a pair was available (only the existence was known). In this paper,…

Algebraic Geometry · Mathematics 2014-02-26 Christophe Eyral , Mutsuo Oka

We construct explicit geometric models for and compute the fundamental groups of all plane sextics with simple singularities only and with at least one type $\bold E_8$ singular point. In particular, we discover four new sextics with…

Algebraic Geometry · Mathematics 2016-01-19 Alex Degtyarev

In this paper we show a Zariski pair of sextics which is not a degeneration of the original example given by Zariski. This is the first example of this kind known. The two curves of the pair have a trivial Alexander polynomial. The…

Algebraic Geometry · Mathematics 2007-05-23 E. Artal Bartolo , J. Carmona Ruber , J. I. Cogolludo , Hiro-o Tokunaga

In this paper we discuss some properties of fundamental groups and Alexander polynomials of plane curves. We discuss the relationship of the non-triviality of Alexander polynomials and the notion of (nearly) freeness for irreducible plane…

Algebraic Geometry · Mathematics 2017-08-30 Enrique Artal Bartolo , Alexandru Dimca

We prove Libgober's divisibility relations for Oka and Alexander polynomials of symplectic curves in the complex projective plane. Along the way, we give new proofs of the divisibility relations for the Alexander polynomials of complex…

Geometric Topology · Mathematics 2026-01-26 Hanine Awada , Marco Golla

We derive explicit defining equations for a number of irreducible maximizing plane sextics with double singular points only. For most real curves, we also compute the fundamental group of the complement; all groups found are abelian. As a…

Algebraic Geometry · Mathematics 2014-09-25 Alex Degtyarev

Alexander polynomials of sextics with only simple singularities or sextics of torus type with arbitrary singularities are computed. We show that for ieeducible sextics,there are four possibilities: $(t^2-t+1)^j, j=0,1,2,3$.

Algebraic Geometry · Mathematics 2007-05-23 Mutsuo Oka

We analyze irreducible plane sextics whose fundamental group factors to $D_{14}$. We produce explicit equations for all curves and show that, in the simplest case of the set of singularities $3A_6$, the group is $D_{14}\times Z_3$.

Algebraic Geometry · Mathematics 2010-05-07 Alex Degtyarev , Mutsuo Oka

We calculate the fundamental groups $\pi=\pi_1(P^2\setminus B)$ for all irreducible plane sextics $B\subset\P^2$ with simple singularities for which $\pi$ is known to admit a dihedral quotient $D_{10}$. All groups found are shown to be…

Algebraic Geometry · Mathematics 2010-05-07 Alex Degtyarev

We show that the fundamental group of the complement of any irreducible tame torus sextics in $\bf P^2$ is isomorphic to $\bf Z_2*\bf Z_3$ except one class. The exceptional class has the configuration of the singularities $\{C_{3,9},3A_2\}$…

Algebraic Geometry · Mathematics 2007-05-23 Mutsuo Oka , Duc Tai Pho

We start with a discussion on Alexander invariants, and then prove some general results concerning the divisibility of the Alexander polynomials and the supports of the Alexander modules, via Artin's vanishing theorem for perverse sheaves.…

Algebraic Topology · Mathematics 2012-04-03 Alexandru Dimca , Laurentiu Maxim

Let X be an irreducible hypersurface in $\mathbb{P}^n$ of degree $d\geq 3$ with only isolated semi-weighted homogeneous singularities, such that $exp(\frac{2\pi i}{k})$ is a zero of the Alexander polynomial. Then we show that the…

Algebraic Geometry · Mathematics 2023-10-10 Remke Kloosterman

We study complex plane projective sextic curves with simple singularities up to equisingular deformations. It is shown that two such curves are deformation equivalent if and only if the corresponding pairs are diffeomorphic. A way to…

Algebraic Geometry · Mathematics 2008-03-21 Alex Degtyarev

We prove Horrocks' theorem for the odd elementary orthogonal group, which gives a decomposition of an orthogonal matrix with entries from a polynomial ring $R[X]$, over a commutative ring $R$ in which 2 is invertible, as a product of an…

K-Theory and Homology · Mathematics 2025-06-13 Ambily A A , Sugilesh H

We give a complete deformation classification of real Zariski sextics, that is of generic apparent contours of nonsingular real cubic surfaces. As a by-product, we observe a certain "reversion" duality in the set of deformation classes of…

Algebraic Geometry · Mathematics 2015-02-10 Sergey Finashin , Viatcheslav Kharlamov

The complete list of reducible sextics of torus type with simple singularities is known in our previous paper. In this paper, we give a complete list of existence and non-existence of Zariski partner sextics of non-torus type corresponding…

Algebraic Geometry · Mathematics 2007-05-23 Mutsuo Oka
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