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Vector bundles trivialized by proper morphisms and the fundamental group scheme

Published online by Cambridge University Press:  24 February 2010

Indranil Biswas
Affiliation:
School of Mathematics, Tata Institute of Fundamental Research, Homi Bhabha Road, Bombay 400005, India, (indranil@math.tifr.res.in)
João Pedro P. Dos Santos
Affiliation:
Université de Paris 6, Institut de Mathématiques de Jussieu, 175, Rue du Chevaleret, 75013 Paris, France, (dos-santos@math.jussieu.fr)

Abstract

Let X be a smooth projective variety defined over an algebraically closed field k. Nori constructed a category of vector bundles on X, called essentially finite vector bundles, which is reminiscent of the category of representations of the fundamental group (in characteristic zero). In fact, this category is equivalent to the category of representations of a pro-finite group scheme which controls all finite torsors. We show that essentially finite vector bundles coincide with those which become trivial after being pulled back by some proper and surjective morphism to X.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2010

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References

1.Atiyah, M. F., On the Krull-Schmidt theorem with application to sheaves, Bull. Soc. Math. France 84 (1956), 307317.CrossRefGoogle Scholar
2.Biswas, I., Parameswaran, A. J. and Subramanian, S., Monodromy group for a strongly semistable principal bundle over a curve, Duke Math. J. 132 (2006), 148.CrossRefGoogle Scholar
3.Deligne, P. and Milne, J., Tannakian categories, in Hodge cycles, motives, and Shimura varieties (ed. Deligne, P., Milne, J. S., Ogus, A. and Shih, K.-Y.), Lecture Notes in Mathematics, Volume 900, pp. 101228 (Springer, 1982).Google Scholar
4.Grothendieck, A., Revêtements étales et groupe fondamental, Lecture Notes in Mathematics, Volume 224 (Springer, 1972).Google Scholar
5.Hartshorne, R., Algebraic geometry, Graduate Texts in Mathematics, No. 52 (Springer, 1977).Google Scholar
6.Lange, H. and Stuhler, U., Vektorbündel auf Kurven und Darstellungen der algebraischen Fundamentalgruppe, Math. Z. 156 (1977), 7383.CrossRefGoogle Scholar
7.Langer, A., Semistable sheaves in positive characteristic, Annals Math. 159 (2004), 251276.Google Scholar
8.Langer, A., On the S-fundamental group scheme, preprint (arXiv:0905.4600V1, May 2009).Google Scholar
9.Nitsure, N., Construction of Hilbert and Quot schemes, in Fundamental algebraic geometry, Mathematical Surveys and Monographs, Volume 123 (American Mathematical Society, Providence, RI, 2005).Google Scholar
10.Nori, M. V., On the representations of the fundamental group, Compositio Math. 33 (1976), 2941.Google Scholar