Full paper in PDF:
$%F. Ronga, A. Tognoli, and T. Vust, The number of conics tangent to five given conics: the real
case, Rev. Mat. Univ. Complut. Madrid 10 (1997), no. 2, 391–421.%$
Section de Mathématiques Université de Genève C.P. 240, CH-1211 Genéve 24 — Switzerland | Dipartimento di Matematica Università degli Studi Via Sommarive 14 I-38050 Povo (Trento) — Italy |
It is a classical result, first established by de Jonquières (1859), that generically the number of conics tangent to 5 given conics in the complex projective plane is 3264. We show here the existence of configurations of 5 real conics such that the number of real conics tangent to them is 3264.
1991 Mathematics Subject Classification: 14P25, 14N10.