Abstract
The aim of this paper is to identify a certain tensor category of perverse sheaves on the loop Grassmannian Grℝ of a real form Gℝ of a connected reductive complex algebraic group G with the category of finite-dimensional representations of a connected reductive complex algebraic subgroup \(\check{H}\) of the dual group \(\check{G}\). The root system of \(\check{H}\) is closely related to the restricted root system of Gℝ. The fact that \(\check{H}\) is reductive implies that an interesting family of real algebraic maps satisfies the conclusion of the Decomposition Theorem of Beilinson-Bernstein-Deligne.
We’re sorry, something doesn't seem to be working properly.
Please try refreshing the page. If that doesn't work, please contact support so we can address the problem.
References
Araki, S.: On root systems and an infinitesimal classification of irreducible symmetric spaces. J. Math. Osaka City Univ. 13, 1–34 (1962)
Beilinson, A.A., Bernstein, J., Deligne, P.: Faisceaux pervers. In: Analysis and topology on singular spaces, I (Luminy, 1981), pp. 5–171. Paris: Soc. Math. France 1982
Beilinson, A., Drinfeld, V.: Quantization of Hitchin’s integrable system and Hecke eigensheaves. In preparation
Braverman, A., Finkelberg, M., Gaitsgory, D., Mirković, I.: Intersection cohomology of Drinfeld’s compactifications. Sel. Math., New Ser. 8, 381–418 (2002)
Braverman, A., Gaitsgory, D.: Crystals via the affine Grassmannian. Duke Math. J. 107, 561–575 (2001)
Braverman, A., Gaitsgory, D.: Geometric Eisenstein series. Invent. Math. 150, 287–384 (2002)
Beauville, A., Laszlo, Y.: Conformal blocks and generalized theta functions. Commun. Math. Phys. 164, 385–419 (1994)
Bernstein, J., Lunts, V.: Equivariant sheaves and functors. Berlin: Springer 1994
Deligne, P., Milne, J.S.: Tannakian categories. In: Hodge cycles, motives, and Shimura varieties, pp. 101–228. Lect. Notes Math. 900. Berlin: Springer 1982
Frenkel, E., Gaitsgory, D., Vilonen, K.: Whittaker patterns in the geometry of moduli spaces of bundles on curves. Ann. Math. (2) 153, 699–748 (2001)
Gaitsgory, D.: Construction of central elements in the affine Hecke algebra via nearby cycles. Invent. Math. 144, 253–280 (2001)
Ginzburg, V.: Perverse sheaves on a loop group and Langlands duality. Preprint math.AG/9511007, 1996
Goresky, M., MacPherson, R.: Morse theory and intersection homology theory. In: Analysis and topology on singular spaces, II, III (Luminy, 1981), pp. 135–192. Paris: Soc. Math. France 1983
Goresky, M., MacPherson, R.: Stratified Morse theory. In: Ergebnisse der Mathematik und ihrer Grenzgebiete (3) [Results in Mathematics and Related Areas (3)], vol. 14. Berlin: Springer 1988
Goresky, M., MacPherson, R.: Local contribution to the Lefschetz fixed point formula. Invent. Math. 111, 1–33 (1993)
Helgason, S.: Differential geometry, Lie groups, and symmetric spaces. Pure and Applied Mathematics, vol. 80. New York: Academic Press Inc. [Harcourt Brace Jovanovich Publishers] 1978
Iwahori, N., Matsumoto, H.: On some Bruhat decomposition and the structure of the Hecke rings of p-adic Chevalley groups. Publ. Math., Inst. Hautes Étud. Sci. 25, 5–48 (1965)
Laszlo, Y., Sorger, C.: The line bundles on the moduli of parabolic G-bundles over curves and their sections. Ann. Sci. Éc. Norm. Supér., IV. Sér. 30, 499–525 (1997)
Lusztig, G.: Singularities, character formulas, and a q-analog of weight multiplicities. In: Analysis and topology on singular spaces, II, III (Luminy, 1981), pp. 208–229. Paris: Soc. Math. France 1983
Mather, J.: Notes on topological stability. Harvard University 1970
Milnor, J.: Singular points of complex hypersurfaces. Annals of Mathematics Studies, No. 61. Princeton, N.J.: Princeton University Press 1968
Mitchell, S.A.: Quillen’s theorem on buildings and the loops on a symmetric space. Enseign. Math., II. Sér. 34, 123–166 (1988)
Mirković, I., Vilonen, K.: Perverse sheaves on affine Grassmannians and Langlands duality. Math. Res. Lett. 7, 13–24 (2000)
Mirković, I., Vilonen, K.: Geometric Langlands duality and representations of algebraic groups over commutative rings. Preprint math.RT/0401222, 2004
Nichols, W.D.: Quotients of Hopf algebras. Commun. Algebra 6, 1789–1800 (1978)
Ngô, B.C., Polo, P.: Résolutions de Demazure affines et formule de Casselman-Shalika géométrique. J. Algebr. Geom. 10, 515–547 (2001)
Pressley, A., Segal, G.: Loop groups. Oxford Science Publications. New York: The Clarendon Press Oxford University Press 1986
Springer, T.A.: Reductive groups. In: Automorphic forms, representations and L-functions (Proc. Sympos. Pure Math., Oregon State Univ., Corvallis, OR, 1977), Part 1, pp. 3–27. Providence, R.I.: Am. Math. Soc. 1979
Springer, T.A.: Linear algebraic groups, second edn. Boston, MA: Birkhäuser Boston Inc. 1998
Rivano, N.S.: Catégories Tannakiennes. Lect. Notes Math. 265. Berlin: Springer 1972
Ulbrich, K.-H.: On Hopf algebras and rigid monoidal categories. Isr. J. Math. 72, 252–256 (1990)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Nadler, D. Perverse sheaves on real loop Grassmannians. Invent. math. 159, 1–73 (2005). https://doi.org/10.1007/s00222-004-0382-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00222-004-0382-3