RT Journal Article T1 Proof of Schubert's conjectures on double contacts. A1 Arrondo Esteban, Enrique A1 Mallavibarrena Martínez de Castro, Raquel A1 Sols Lucía, Ignacio AB The purpose of the paper under review is to give a proof of six formulas by Schubert (two of which he proved and four of which he only conjectured) concerning the number of double contacts among the curves of two families of plane curves. The method consists in finding bases of the Chow groups of the Hilbert scheme of length 2 subschemes of the point- line incidence variety. This approach turns out to be much simpler than the one using the space of triangles as suggested by Schubert.As a byproduct, the authors obtain proofs of the classical formulas on triple contacts (i.e., single contacts of third order) between two such families of curves PB Springer SN 0075-8434 YR 1990 FD 1990 LK https://hdl.handle.net/20.500.14352/58341 UL https://hdl.handle.net/20.500.14352/58341 NO Proceedings of the conference held in Sitges, June 1–6, 1987 DS Docta Complutense RD 25 feb 2026