Real plane sextics without real points
Authors:
Alex Degtyarev and Ilia Itenberg
Journal:
J. Algebraic Geom. 34 (2025), 543-577
DOI:
https://doi.org/10.1090/jag/844
Published electronically:
March 24, 2025
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Abstract |
References |
Additional Information
Abstract: We prove that the equisingular deformation type of a simple real plane sextic curve with smooth real part is determined by its real homological type, i.e., the polarization, exceptional divisors, and real structure recorded in the homology of the covering $K3$-surface. As an illustration, we obtain an equisingular deformation classification of real plane sextics with empty real part (for completeness, we consider the few non-simple ones as well).
References
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- Anatoly Libgober, Braid monodromy and Alexander polynomials of real plane curves, Beitr. Algebra Geom. 65 (2024), no. 3, 455–474. MR 4779534, DOI 10.1007/s13366-023-00700-3
- Rick Miranda and David R. Morrison, Embeddings of integral quadratic forms, Electronic, 2009, http://www.math.ucsb.edu/~drm/manuscripts/eiqf.pdf.
- V. V. Nikulin, Integer symmetric bilinear forms and some of their geometric applications, Izv. Akad. Nauk SSSR Ser. Mat. 43 (1979), no. 1, 111–177, 238 (Russian). MR 525944
- Viacheslav V. Nikulin, Weil linear systems on singular $K3$ surfaces, Algebraic geometry and analytic geometry (Tokyo, 1990) ICM-90 Satell. Conf. Proc., Springer, Tokyo, 1991, pp. 138–164. MR 1260944
- I. I. Pjateckiĭ-Šapiro and I. R. Šafarevič, Torelli’s theorem for algebraic surfaces of type $\textrm {K}3$, Izv. Akad. Nauk SSSR Ser. Mat. 35 (1971), 530–572 (Russian). MR 284440
- B. Saint-Donat, Projective models of $K-3$ surfaces, Amer. J. Math. 96 (1974), 602–639. MR 364263, DOI 10.2307/2373709
- Ichiro Shimada, Lattice Zariski $k$-ples of plane sextic curves and $Z$-splitting curves for double plane sextics, Michigan Math. J. 59 (2010), no. 3, 621–665. MR 2745755, DOI 10.1307/mmj/1291213959
- È. B. Vinberg, The groups of units of certain quadratic forms, Mat. Sb. (N.S.) 87(129) (1972), 18–36 (Russian). MR 295193
- Jin-Gen Yang, Sextic curves with simple singularities, Tohoku Math. J. (2) 48 (1996), no. 2, 203–227. MR 1387816, DOI 10.2748/tmj/1178225377
References
- Ayşegül Akyol, Classical Zariski pairs, J. Knot Theory Ramifications 21 (2012), no. 9, 1250091, 16. MR 2926574, DOI 10.1142/S0218216512500915
- Ayşegül Akyol and Alex Degtyarev, Geography of irreducible plane sextics, Proc. Lond. Math. Soc. (3) 111 (2015), no. 6, 1307–1337. MR 3447795, DOI 10.1112/plms/pdv053
- V. I. Arnol′d, S. M. Guseĭn-Zade, and A. N. Varchenko, Singularities of differentiable maps. Vol. I, Monographs in Mathematics, vol. 82, Birkhäuser Boston, Inc., Boston, MA, 1985. The classification of critical points, caustics and wave fronts; Translated from the Russian by Ian Porteous and Mark Reynolds. MR 777682, DOI 10.1007/978-1-4612-5154-5
- Wolf P. Barth, Klaus Hulek, Chris A. M. Peters, and Antonius Van de Ven, Compact complex surfaces, 2nd ed., Ergebnisse der Mathematik und ihrer Grenzgebiete. 3. Folge. A Series of Modern Surveys in Mathematics [Results in Mathematics and Related Areas. 3rd Series. A Series of Modern Surveys in Mathematics], vol. 4, Springer-Verlag, Berlin, 2004. MR 2030225, DOI 10.1007/978-3-642-57739-0
- Arnaud Beauville, Application aux espaces de modules, Astérisque 126 (1985), 141–152 (French). Geometry of $K3$ surfaces: moduli and periods (Palaiseau, 1981/1982). MR 785231
- Alex Degtyarev, Fundamental groups of symmetric sextics, J. Math. Kyoto Univ. 48 (2008), no. 4, 765–792. MR 2513586, DOI 10.1215/kjm/1250271318
- Alex Degtyarev, On deformations of singular plane sextics, J. Algebraic Geom. 17 (2008), no. 1, 101–135. MR 2357681, DOI 10.1090/S1056-3911-07-00469-9
- Alex Degtyarev, Stable symmetries of plane sextics, Geom. Dedicata 137 (2008), 199–218. MR 2449152, DOI 10.1007/s10711-008-9293-6
- Alex Degtyarev, Fundamental groups of symmetric sextics. II, Proc. Lond. Math. Soc. (3) 99 (2009), no. 2, 353–385. MR 2533669, DOI 10.1112/plms/pdp003
- Alex Degtyarev, Irreducible plane sextics with large fundamental groups, J. Math. Soc. Japan 61 (2009), no. 4, 1131–1169. MR 2588507
- Alex Degtyarev, On irreducible sextics with non-abelian fundamental group, Singularities—Niigata–Toyama 2007, Adv. Stud. Pure Math., vol. 56, Math. Soc. Japan, Tokyo, 2009, pp. 65–91. MR 2604077, DOI 10.2969/aspm/05610065
- A. Degtyarev, I. Itenberg, and V. Kharlamov, Real Enriques surfaces, Lecture Notes in Mathematics, vol. 1746, Springer-Verlag, Berlin, 2000. MR 1795406, DOI 10.1007/BFb0103960
- Leonard Eugene Dickson, Modern elementary theory of numbers, University of Chicago Press, Chicago, IL, 1939. MR 387
- I. V. Dolgachev, Mirror symmetry for lattice polarized $K3$ surfaces, J. Math. Sci. 81 (1996), no. 3, 2599–2630. Algebraic geometry, 4. MR 1420220, DOI 10.1007/BF02362332
- D. A. Gudkov, G. A. Utkin, and M. L. Taĭ, A complete classification of indecomposable curves of the fourth order, Mat. Sb. (N.S.) 69(111) (1966), 222–256 (Russian). MR 198335
- I. V. Itenberg, Curves of degree $6$ with one nondegenerate double point and groups of monodromy of nonsingular curves, Real algebraic geometry (Rennes, 1991) Lecture Notes in Math., vol. 1524, Springer, Berlin, 1992, pp. 267–288. MR 1226259, DOI 10.1007/BFb0084626
- Andrés Jaramillo Puentes, Rigid isotopy classification of generic rational curves of degree 5 in the real projective plane, Geom. Dedicata 211 (2021), 1–70. MR 4228493, DOI 10.1007/s10711-020-00540-8
- Johannes Josi, Real nodal sextics without real nodes, arXiv:1704.00950, 2017.
- Johannes Josi, Nodal rational sextics in the real projective plane, PhD diss., Sorbonne Université and Université de Genève, 2018.
- V. M. Kharlamov, Rigid classification up to isotopy of real plane curves of degree $5$, Funktsional. Anal. i Prilozhen. 15 (1981), no. 1, 88–89 (Russian). MR 609806
- Vik. S. Kulikov, Surjectivity of the period mapping for $K3$ surfaces, Uspehi Mat. Nauk 32 (1977), no. 4(196), 257–258 (Russian). MR 480528
- Anatoly Libgober, Braid monodromy and Alexander polynomials of real plane curves, Beitr. Algebra Geom. 65 (2024), no. 3, 455–474. MR 4779534, DOI 10.1007/s13366-023-00700-3
- Rick Miranda and David R. Morrison, Embeddings of integral quadratic forms, Electronic, 2009, http://www.math.ucsb.edu/~drm/manuscripts/eiqf.pdf.
- V. V. Nikulin, Integer symmetric bilinear forms and some of their geometric applications, Izv. Akad. Nauk SSSR Ser. Mat. 43 (1979), no. 1, 111–177, 238 (Russian). MR 525944
- Viacheslav V. Nikulin, Weil linear systems on singular $K3$ surfaces, Algebraic geometry and analytic geometry (Tokyo, 1990) ICM-90 Satell. Conf. Proc., Springer, Tokyo, 1991, pp. 138–164. MR 1260944
- I. I. Pjateckiĭ-Šapiro and I. R. Šafarevič, Torelli’s theorem for algebraic surfaces of type $\mathrm {K}3$, Izv. Akad. Nauk SSSR Ser. Mat. 35 (1971), 530–572 (Russian). MR 284440
- B. Saint-Donat, Projective models of $K-3$ surfaces, Amer. J. Math. 96 (1974), 602–639. MR 364263, DOI 10.2307/2373709
- Ichiro Shimada, Lattice Zariski $k$-ples of plane sextic curves and $Z$-splitting curves for double plane sextics, Michigan Math. J. 59 (2010), no. 3, 621–665. MR 2745755, DOI 10.1307/mmj/1291213959
- È. B. Vinberg, The groups of units of certain quadratic forms, Mat. Sb. (N.S.) 87(129) (1972), 18–36 (Russian). MR 295193
- Jin-Gen Yang, Sextic curves with simple singularities, Tohoku Math. J. (2) 48 (1996), no. 2, 203–227. MR 1387816, DOI 10.2748/tmj/1178225377
Additional Information
Alex Degtyarev
Affiliation:
Department of Mathematics, Bilkent University, 06800 Ankara, Turkey
MR Author ID:
271103
ORCID:
0000-0001-6586-4094
Email:
degt@fen.bilkent.edu.tr
Ilia Itenberg
Affiliation:
IMJ-PRG, Sorbonne Université and Université Paris Cité, CNRS, F-75005 Paris, France
MR Author ID:
321564
ORCID:
0000-0003-3216-1581
Email:
ilia.itenberg@imj-prg.fr
Received by editor(s):
March 12, 2024
Received by editor(s) in revised form:
September 15, 2024, and October 18, 2024
Published electronically:
March 24, 2025
Additional Notes:
The first author was partially supported by the TÜBİTAK grant 123F111. The second author was supported in part by the ANR grants ANR-18-CE40-0009 ENUMGEOM and ANR-22-CE40-0014 SINTROP.
Article copyright:
© Copyright 2025
University Press, Inc.