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Singularities of plane rational curves via projections. (English) Zbl 1390.14183

In this note, the authors tackle a problem of determining singularities of a plane rational curve \(C\) from its parameterization \(\mathbf{f}=(f_0:f_1:f_2)\). In order to study the singularities of \(C\) of degree \(n\), they use the fact that the parameterization of \(C\) defines a projection \(\pi:\mathbb{P}^n\dashrightarrow\mathbb{P}^2\), which is generically one-to-one from the rational normal curve \(C_n\subset\mathbb{P}^n\) onto its image \(\pi(C_n)=C\subset\mathbb{P}^2\). Then they explore the secant varieties to \(C_n\). In particular, they define via \(\mathbf{f}\) certain \(0\)-dimensional schemes \(X_k\subset\mathbb{P}^k\), \(2\leq k\leq (n-1)\), which encode all information on the singularities of multiplicity \(\geq k\) of \(C\).
The authors give also a series of algorithms which allow one to obtain information about the singularities of \(C\) from such schemes \(X_k\). The algorithms presented in the paper in pseudo code can be easily implemented in symbolic algebra programs such as CoCoA, Macaulay2 or Bertini.
Editorial remark: in [A. Gimigliano and M. Idà, Geom. Dedicata 217, No. 1, Paper No. 5, 14 p. (2023; Zbl 1504.14057)], the last two authors give a counterexample to Lemma 4.2.

MSC:

14Q05 Computational aspects of algebraic curves
68W30 Symbolic computation and algebraic computation

Citations:

Zbl 1504.14057

References:

[1] Banica, C.; Stanasila, O., Méthode algébriques dans la théorie globale des espaces complexes (1977), Ed. ACADEMIEI et Gauthier-Villars Ed.: Ed. ACADEMIEI et Gauthier-Villars Ed. Paris · Zbl 0349.32006
[2] Bates, D. J.; Hauenstein, J. D.; Sommese, A. J.; Wampler, C. W., Bertini: software for numerical algebraic geometry (2013), Available at
[3] Bernardi, A.; Daleo, N. S.; Hauenstein, J. D.; Mourrain, B., Tensor decomposition and homotopy continuation (2015), Available at
[4] Bernardi, A.; Gimigliano, A.; Idà, M., Computing symmetric rank for symmetric tensors, J. Symb. Comput., 46, 34-53 (2011) · Zbl 1211.14057
[5] Bernardi, A.; Gimigliano, A.; Idà, M., A note on plane rational curves and the associated Poncelet Surfaces, Rend. Ist. Mat. Univ. Trieste, 47, 1-6 (2015) · Zbl 1344.14020
[6] Bernardi, A.; Gimigliano, A.; Idà, M., On parameterizations of plane rational curves and their syzygies, Math. Nachr., 289, 537-545 (2016) · Zbl 1342.14064
[7] Capani, A.; Niesi, G.; Robbiano, L., CoCoA, a system for doing Computations in Commutative Algebra (1995), Available via anonymous ftp from
[8] Chen, F.; Wang, W.; Liu, Y., Computing singular points of plane rational curves, J. Symb. Comput., 43, 92-117 (2008) · Zbl 1130.14039
[9] Cox, D.; Sederburg, T. W.; Chen, F., The moving line ideal basis of planar rational curves, Comput. Aided Geom. Des., 15, 803-827 (1998) · Zbl 0908.68174
[10] Cox, D.; Kustin, A. R.; Polini, C.; Ulrich, B., A study of singularities on rational curves via syzygies, Mem. Am. Math. Soc., 222, 1045 (2013) · Zbl 1305.14014
[11] Eagon, J.; Northcott, D. G., Ideals defined by matrices and a certain complex associated to them, Proc. R. Soc. Ser. A, 269, 188-204 (1962) · Zbl 0106.25603
[12] Flenner, H.; Zaidenberg, M., On a class of rational cuspidal plane curves, Manuscr. Math., 89, 439-459 (1996) · Zbl 0868.14014
[13] Grayson, D. R.; Stillman, M. E., Macaulay2, a software system for research in algebraic geometry (2009), Available at
[14] Greuel, G.-M.; Lossen, C.; Shustin, E. I., Introduction to Singularities and Deformations, Springer Monographs in Mathematics (2007) · Zbl 1125.32013
[15] Hartshorne, B., Algebraic Geometry, Grad. Texts in Math., vol. 52 (1977), Springer: Springer Berlin, Heidelberg, New York · Zbl 0367.14001
[16] Ilardi, G.; Supino, P.; Valles, J., Geometry of syzygies via Poncelet varieties, Boll. UMI, serie IX, II (2009) · Zbl 1197.13013
[17] Kleimann, S.; Piene, R., Enumerating singular curves on surfaces, (Algebraic Geometry: Hirzebruch 70. Algebraic Geometry: Hirzebruch 70, Warsaw, 1998. Algebraic Geometry: Hirzebruch 70. Algebraic Geometry: Hirzebruch 70, Warsaw, 1998, Contemp. Math., vol. 241 (1999), Amer. Math. Soc.: Amer. Math. Soc. Providence, RI), 209-238 · Zbl 0953.14031
[18] Moe, T. K., Rational Cuspidal Curves (2008), University of Oslo, Available at
[19] Orevkov, S. Y., On rational cuspidal curves. I. Sharp estimate for degree via multiplicities, Math. Ann., 324, 657-673 (2002) · Zbl 1014.14010
[20] Pèrez-Dìaz, S., Computation of the singularities of parametric plane curves, J. Symb. Comput., 42, 835-857 (2007) · Zbl 1138.14036
[21] Piene, R., Cuspidal projections of space curves, Math. Ann., 256, 95-119 (1981) · Zbl 0468.14010
[22] Schwarzenberger, R. L.E., Proc. Lond. Math. Soc., 3-14 (1964), 369-384 · Zbl 0123.38201
[23] Sendra, J.; Winkler, F.; Pèrez-Dìaz, S., Rational Algebraic Curves. A Computer Algebra Approach, Algorithms and Computation in Mathematics, vol. 22 (2008), Springer-Verlag: Springer-Verlag Berlin · Zbl 1129.14083
[24] Song, N.; Chen, F.; Goldman, R., Axial moving lines and singularities of rational planar curves, Comput. Aided Geom. Des., 24, 200-209 (2007) · Zbl 1171.65352
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