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Related papers: Classical Zariski pairs

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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 partially prove and partially disprove Oka's conjecture on the fundamental group/Alexander polynomial of an irreducible plane sextic. Among other results, we enumerate all irreducible sextics with simple singularities admitting dihedral…

Algebraic Geometry · Mathematics 2008-10-24 Alex Degtyarev

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

A couple of complex projective plane curves are said to make a Zariski pair if they have the same degree and the same type of singularities, but their embeddings in the projective plane are topologically different. In this paper, we present…

alg-geom · Mathematics 2008-02-03 Ichiro Shimada

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 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

A series of Zariski pairs and four Zariski triplets were found by using lattice theory of K3 surfaces. There is a Zariski triplet of which one member is a deformation of another.

Algebraic Geometry · Mathematics 2009-04-10 Jin-Gen Yang , Jinjing Xie

We study the moduli spaces and compute the fundamental groups of plane sextics of torus type with the set of inner singularities $2\bold{A}_8$ or $\bold{A}_{17}$. We also compute the fundamental groups of a number of other sextics, both of…

Algebraic Geometry · Mathematics 2011-07-29 Alex Degtyarev

We construct exponentially large collections of pairwise distinct equisingular deformation families of irreducible plane curves sharing the same sets of singularities. The fundamental groups of all curves constructed are abelian.

Algebraic Geometry · Mathematics 2009-07-02 Alex Degtyarev

We find a new Zariski pair with non-isomorphic fundamental groups that consists of degree $ 8 $ conic-line arrangements. Each arrangement has three conics and two lines. We use the Zariski-van Kampen Theorem and some known Coxeter groups to…

Algebraic Geometry · Mathematics 2025-03-26 Meirav Amram , Robert Shwartz , Uriel Sinichkin , Sheng-Li Tan , Hiro-o Tokunaga

We formulate and prove a weighted version of Zariski's hyperplane section theorem on the topological fundamental groups of the complements of hypersurfaces in a projective space. As an application, we calculate fundamental groups of the…

alg-geom · Mathematics 2008-02-03 Ichiro Shimada

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

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

We study the moduli spaces and compute the fundamental groups of plane sextics of torus type with at least two type $\bold{E}_6$ singular points. As a simple application, we compute the fundamental groups of 125 other sextics, most of which…

Algebraic Geometry · Mathematics 2009-02-13 Alex Degtyarev

In this paper, complement-equivalent arithmetic Zariski pairs will be exhibited answering in the negative a question by Eyral-Oka on these curves and their groups. A complement-equivalent arithmetic Zariski pair is a pair of complex…

Algebraic Geometry · Mathematics 2018-05-04 E. Artal Bartolo , J. I. Cogolludo-Agustín

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

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 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 define a topological invariant of complex projective plane curves. As an application, we present new examples of arithmetic Zariski pairs.

Algebraic Geometry · Mathematics 2007-05-23 Ichiro Shimada

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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