Pencils of curves with 4 or 6 Conic-Line Curves


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Suluyer H.

Topology of Arrangements with an Eye to Applications, Pisa, İtalya, 1 - 05 Eylül 2025, (Yayınlanmadı)

  • Yayın Türü: Bildiri / Yayınlanmadı
  • Basıldığı Şehir: Pisa
  • Basıldığı Ülke: İtalya
  • Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

 A pencil of degree d > curves is a line in the projective space of all homogeneous polynomials in [x0,x1,x2of degree d. The k > curves whose irreducible components are only lines in some pencil of degree curves play an important role for (k,d)-nets. The line arrangement comprised of all these irreducible components has a net structure. It was proved that the number k, independent of d, cannot exceed 4 for an (k,d)-net. When the degree of each irreducible component of a curve is at most 2, this curve is called a conic-line curve and it is a union of lines or irreducible conics in the complex projective plane. The number of such curves in pencils cannot exceed 6.

We study the restrictions on the number of conic-line curves in special pencils. We present a one-parameter family of pencils of cubics with exactly 4 conic-line curves while there exists only one known net with = 4. Moreover, we show the combinatorics of the irreducible components of conic-line curves in odd degree pencils with = 6.