Hostname: page-component-7479d7b7d-wxhwt Total loading time: 0 Render date: 2024-07-11T18:26:48.032Z Has data issue: false hasContentIssue false

Point-curve correspondences

III. Correspondences on a single surface

Published online by Cambridge University Press:  24 October 2008

D. B. Scott
Affiliation:
University of LondonKing's College

Extract

In this paper we consider the theory of point-curve correspondences on a single surface F, i.e. correspondences in which to each point of F corresponds an algebraic curve of F. The results previously obtained for induced and extended correspondences between two surfaces require some modification here, as we can consider the self-correspondences induced on a curve C of F, and the related theory of extended correspondences, which is now complicated by the existence of the identical correspondence on C. We also develop a theory of correspondences with (non-zero) valency, and show that for a surface whose Riemann matrix is pure and without complex multiplication (and hence for surfaces of ‘general moduli’), all correspondences are valency correspondences, this result being exactly analogous to the well-known theorem for curves. We also consider generalized valency correspondences which are an extension to surfaces of the concept of correspondences of multiple valency on a curve. The analogy between our theory and the known results for curves does break down in one important respect. It is not true that every surface possesses valency correspondences even of the generalized kind, the existence of such correspondences involving restrictions on the intersection group of the surface.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1949

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

(1)Baker, H. F.Principles of Geometry, 6 (Cambridge, 1933).Google Scholar
(2)Scott, D. B.Invariant groups associated with an algebraic surface. Proc. Cambridge Phil. Soc. 36 (1940), 414–23.CrossRefGoogle Scholar
(3)Scott, D. B.Point-curve correspondences. I. Proc. Cambridge Phil. Soc. 41 (1945), 135–45.CrossRefGoogle Scholar
(4)Scott, D. B.Point-curve correspondences. II. Proc. Cambridge Phil. Soc. 42 (1946), 229–39.CrossRefGoogle Scholar
(5)Scott, D. B.The united-curve of a point-curve correspondence on an algebraic surface. To appear in Proc. London Math. Soc.Google Scholar
(6)Severi, F.Le corrispondeuze fra i punti di una curva variabile in una sistema lineare sopra una superficie algebriche. Math. Ann. 74 (1913), 515–44.CrossRefGoogle Scholar
(7)Zariski, O. Algebraic surfaces. Ergebn. Math. 3, 5 (Berlin, 1935).Google Scholar