Following Sam Payneʼs work, we study the existence problem of nontrivial vector bundles on toric varieties. The first result we prove is that every complete fan admits a nontrivial conewise linear multivalued function. Such functions could potentially be the Chern classes of toric vector bundles. Then we use the results of Cortiñas, Haesemeyer, Walker and Weibel to show that the (non-equivariant) Grothendieck group of the toric 3-fold studied by Payne is large, so the variety has a nontrivial vector bundle. Using the same computation, we show that every toric 3-fold X either has a nontrivial line bundle, or there is a finite surjective toric morphism from Y to X, such that Y has a large Grothendieck group.
Suivant un travail de Sam Payne nous étudions lʼexistence de fibrés vectoriels non triviaux sur une variété torique. Notre premier résultat établit que tout éventail complet admet une fonction, non triviale, qui est linéaire et multi-valuée sur chaque cône. Une telle fonction peut potentiellement être la classe de Chern dʼun fibré vectoriel torique. Nous utilisons alors un résultat de Cortiñas, Haesemeyer, Walker et Weibel pour montrer que le groupe de Grothendieck (non équivariant) de la variété torique de dimension 3 étudiée par Payne est grand et ainsi la variété a un fibré vectoriel non trivial. Par un calcul similaire nous montrons que pour toute variété torique X de dimension 3, soit X a un fibré en droites non trivial, soit il existe un morphisme torique, surjectif, fini de Y sur X, où Y a un grand groupe de Grothendieck.
Accepted:
Published online:
Saman Gharib 1; Kalle Karu 1
@article{CRMATH_2012__350_3-4_209_0, author = {Saman Gharib and Kalle Karu}, title = {Vector bundles on toric varieties}, journal = {Comptes Rendus. Math\'ematique}, pages = {209--212}, publisher = {Elsevier}, volume = {350}, number = {3-4}, year = {2012}, doi = {10.1016/j.crma.2011.12.013}, language = {en}, }
Saman Gharib; Kalle Karu. Vector bundles on toric varieties. Comptes Rendus. Mathématique, Volume 350 (2012) no. 3-4, pp. 209-212. doi : 10.1016/j.crma.2011.12.013. https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.1016/j.crma.2011.12.013/
[1] Equivariant Chow groups for torus actions, Transform. Groups, Volume 2 (1997) no. 3, pp. 225-267
[2] The K-theory of toric varieties, Trans. Amer. Math. Soc., Volume 361 (2009) no. 6, pp. 3325-3341
[3] Introduction to Toric Varieties, Annals of Mathematics Studies, vol. 131, Princeton University Press, Princeton, NJ, 1993 (The William H. Roever Lectures in Geometry)
[4] Toric varieties with huge Grothendieck group, Adv. Math., Volume 186 (2004) no. 1, pp. 117-124
[5] Equivariant bundles over toric varieties, Izv. Akad. Nauk SSSR Ser. Mat., Volume 53 (1989) no. 5, pp. 1001-1039 (1135)
[6] Comparison of the equivariant and the standard K-theory of algebraic varieties, Algebra i Analiz, Volume 9 (1997) no. 4, pp. 175-214
[7] The K-theory of a toric variety, Adv. Math., Volume 100 (1993) no. 2, pp. 154-182
[8] Equivariant Chow cohomology of toric varieties, Math. Res. Lett., Volume 13 (2006) no. 1, pp. 29-41
[9] Toric vector bundles, branched covers of fans, and the resolution property, J. Algebraic Geom., Volume 18 (2009) no. 1, pp. 1-36
[10] Higher algebraic K-theory for actions of diagonalizable groups, Invent. Math., Volume 153 (2003) no. 1, pp. 1-44
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☆ This work was partially supported by NSERC Discovery and USRA grants.
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