×

Nodal curves with a contact-conic and Zariski pairs. (English) Zbl 1430.14066

Let \(\Gamma\) be an algebraic curve in \(\mathbb{P}^{2}\). A smooth conic \(\Delta\subset\mathbb{P}^{2}\) is called a contact conic of \(\Gamma\) if all of the intersection points of \(\Gamma\) and \(\Delta\) are smooth points of \(\Gamma\) and for them the intersection multiplicity \(I_{P}(\Gamma,\Delta)\geq2\). \(\Gamma\) with even (means intersection multiplicities are even) contact conic \(\Delta\) is a splitting curve of type \((m,n),\) \(m\leq n,\) with respect to \(\Delta\) if for the double cover \(\pi_{\Delta}:X_{\Delta}\rightarrow \mathbb{P}^{2}\) branched along \(\Delta\) the pullback \(\pi_{\Delta}^{\ast}\Gamma=D^{+}+D^{-}\) for an \((m,n)\) divisor \(D^{+}\) on \(X_{\Delta} \cong\mathbb{P}^{1}\times\mathbb{P}^{1}\), where \(D^{-}\) is \(D^{+} \) after the covering transformation of \(X_{\Delta}.\) The main theorem is a criterion for determining the splitting type of a nodal curve \(\Gamma\) (means singular points of \(\Gamma\) are nodes) with respect to an even contact conic in terms of the configuration of the nodes and tangent points of \(\Gamma\) and \(\Delta\). The authors apply the results to Zariski pairs of curves.

MSC:

14H20 Singularities of curves, local rings
14E20 Coverings in algebraic geometry
14H50 Plane and space curves
32S50 Topological aspects of complex singularities: Lefschetz theorems, topological classification, invariants

References:

[1] E. Artal-Bartolo, Sur les couples de Zariski. J. Algebraic Geom. 3 (1994), 223-247. MR1257321 Zbl 0823.14013; Artal-Bartolo, E., Sur les couples de Zariski, J. Algebraic Geom., 3, 223-247 (1994) · Zbl 0823.14013
[2] E. Artal Bartolo, J. Carmona Ruber, J. I. Cogolludo Agustín, Braid monodromy and topology of plane curves. Duke Math. J. 118 (2003), 261-278. MR1980995 Zbl 1058.14053; Artal Bartolo, E.; Carmona Ruber, J.; Cogolludo Agustín, J. I., Braid monodromy and topology of plane curves, Duke Math. J., 118, 261-278 (2003) · Zbl 1058.14053
[3] E. Artal Bartolo, J. I. Cogolludo, H. Tokunaga, A survey on Zariski pairs. In: Algebraic geometry in East Asia—Hanoi 2005, volume 50 of Adv. Stud. Pure Math., 1-100, Math. Soc. Japan, Tokyo 2008. MR2409555 Zbl 1141.14015; Artal Bartolo, E.; Cogolludo, J. I.; Tokunaga, H., Algebraic geometry in East Asia—Hanoi 2005, volume 50 of Adv. Stud. Pure Math., 1-100 (2008) · Zbl 1141.14015
[4] E. Artal Bartolo, H. Tokunaga, Zariski k-plets of rational curve arrangements and dihedral covers. Topology Appl. 142 (2004), 227-233. MR2071304 Zbl 1075.14013; Artal Bartolo, E.; Tokunaga, H., Zariski k-plets of rational curve arrangements and dihedral covers, Topology Appl., 142, 227-233 (2004) · Zbl 1075.14013
[5] S. Bannai, A note on splitting curves of plane quartics and multi-sections of rational elliptic surfaces. Topology Appl. 202 (2016), 428-439. MR3464177 Zbl 1342.14080; Bannai, S., A note on splitting curves of plane quartics and multi-sections of rational elliptic surfaces, Topology Appl., 202, 428-439 (2016) · Zbl 1342.14080
[6] A. B. Coble, Algebraic geometry and theta functions, volume 10 of American Mathematical Society Colloquium Publications. Amer. Math. Soc. 1982. MR733252 JFM 55.0808.02; Coble, A. B., Algebraic geometry and theta functions (1982) · JFM 55.0808.02
[7] A. Degtyarev, On deformations of singular plane sextics. J. Algebraic Geom. 17 (2008), 101-135. MR2357681 Zbl 1131.14040; Degtyarev, A., On deformations of singular plane sextics, J. Algebraic Geom., 17, 101-135 (2008) · Zbl 1131.14040
[8] A. Degtyarev, On the Artal-Carmona-Cogolludo construction. J. Knot Theory Ramifications23 (2014), 1450028, 35pp. MR3233625 Zbl 1309.14025; Degtyarev, A., On the Artal-Carmona-Cogolludo construction, J. Knot Theory Ramifications, 1450028, 35 (2014) · Zbl 1309.14025
[9] A. Dimca, Singularities and topology of hypersurfaces. Springer 1992. MR1194180 Zbl 0753.57001; Dimca, A., Singularities and topology of hypersurfaces. (1992) · Zbl 0753.57001
[10] B. Guerville-Ballé, J.-B. Meilhan, A linking invariant for algebraic curves. Preprint 2016, arXiv:1602.04916 [math.GT]; Guerville-Ballé, B.; Meilhan, J.-B., A linking invariant for algebraic curves. (2016) · Zbl 1468.14063
[11] R. Hartshorne, Algebraic geometry. Springer 1977. MR0463157 Zbl 0367.14001; Hartshorne, R., Algebraic geometry. (1977) · Zbl 0367.14001
[12] C. M. Jessop, Quartic surfaces with singular points. Cambridge University Press 1916. JFM 46.1501.03; Jessop, C. M., Quartic surfaces with singular points. (1916) · JFM 46.1501.03
[13] M. Oka, Symmetric plane curves with nodes and cusps. J. Math. Soc. Japan44 (1992), 375-414. MR1167373 Zbl 0767.14011; Oka, M., Symmetric plane curves with nodes and cusps, J. Math. Soc. Japan, 44, 375-414 (1992) · Zbl 0767.14011
[14] I. Shimada, Lattice Zariski k-ples of plane sextic curves and Z-splitting curves for double plane sextics. Michigan Math. J. 59 (2010), 621-665. MR2745755 Zbl 1230.14041; Shimada, I., Lattice Zariski k-ples of plane sextic curves and Z-splitting curves for double plane sextics, Michigan Math. J., 59, 621-665 (2010) · Zbl 1230.14041
[15] T. Shirane, A note on splitting numbers for Galois covers and \(π_1\)-equivalent Zariski k-plets. Proc. Amer. Math. Soc. 145 (2017), 1009-1017. MR3589301 Zbl 1358.14018; Shirane, T., A note on splitting numbers for Galois covers and \(π_1\)-equivalent Zariski k-plets, Proc. Amer. Math. Soc., 145, 1009-1017 (2017) · Zbl 1358.14018
[16] H. Sumihiro, Elementary transformations of algebraic vector bundles. In: Algebraic and topological theories (Kinosaki, 1984), 305-327, Kinokuniya, Tokyo 1986. MR1102263 Zbl 0800.14008; Sumihiro, H., Algebraic and topological theories (Kinosaki, 1984), 305-327 (1986) · Zbl 0800.14008
[17] H. Tokunaga, Geometry of irreducible plane quartics and their quadratic residue conics. J. Singul. 2 (2010), 170-190. MR2763025 Zbl 1292.14022; Tokunaga, H., Geometry of irreducible plane quartics and their quadratic residue conics, J. Singul., 2, 170-190 (2010) · Zbl 1292.14022
[18] H. Tokunaga, A note on quadratic residue curves on rational ruled surfaces. In: Galois-Teichmüller theory and arithmetic geometry, volume 63 of Adv. Stud. Pure Math., 565-577, Math. Soc. Japan, Tokyo 2012. MR3051255 Zbl 1325.14028; Tokunaga, H., Galois-Teichmüller theory and arithmetic geometry, volume 63 of Adv. Stud. Pure Math., 565-577 (2012) · Zbl 1325.14028
[19] O. Zariski, On the Problem of Existence of Algebraic Functions of Two Variables Possessing a Given Branch Curve. Amer. J. Math. 51 (1929), 305-328. MR1506719 JFM 55.0806.01; Zariski, O., On the Problem of Existence of Algebraic Functions of Two Variables Possessing a Given Branch Curve, Amer. J. Math., 51, 305-328 (1929) · JFM 55.0806.01
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.