Hostname: page-component-848d4c4894-hfldf Total loading time: 0 Render date: 2024-06-08T15:06:40.735Z Has data issue: false hasContentIssue false

Indecomposable Vector Bundles on the Projective Line

Published online by Cambridge University Press:  20 November 2018

Leslie G. Roberts*
Affiliation:
Queen's University, Kingston, Ontario
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Let A be a commutative ring, and let Proj A[t0, ti]. By a vector bundle on X we mean a locally free sheaf of finite rank on X. Set t = t1/to. Then X is made up of two affine pieces U1 = Spec A[t], and U2 = Spec A[t-1]. Let P(R) denote the category of finitely generated projective modules over the ring R. The category of vector bundles on X is equivalent to the category of triples (P1,f1, P2), where P1𝓅 (A[t]), P2 ∊ 𝓅(A[t-1]), and

is an A[t, t-1] -isomorphism. In [2], the category of vector bundles on is denned directly in this manner, without first defining (so that one could work over a non-commutative ring). We prove that if A is a Krull ring (or a Noetherian ring with connected spec) of dimension > 0, then there is an indecomposable vector bundle of rank n on X, for every positive integer n.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1972

References

1. Atiyah, M. F., On the Krull-Schmidt theorem with applications to sheaves, Bull. Soc. Math. France 84 (1956), 307–17.Google Scholar
2. Bass, H., Algebraic K-theory (Benjamin, New York, 1968).Google Scholar
3. Bass, H., Corrections and supplements to “Algebraic K-theory”, Mimeographed notes, Columbia University, 1970.Google Scholar
4. Grothendieck, A., Sur la classification des fibres holomorphes sur la sphère de Riemann, Amer. J. Math. 79 (1957) 121–38.Google Scholar
5. Grothendieck, A. and Dieudonné, J., Elements de géometrie algébrique. II, Publications Mathématique de l'Institute des Hautes Etudes Scientifiques, No. 8 (1961).Google Scholar