Skip to main content

Equivariant Hirzebruch class for singular varieties

Abstract

We develop an equivariant version of the Hirzebruch class for singular varieties. When the group acting is a torus we apply localization theorem of Atiyah–Bott and Berline–Vergne. The localized Hirzebruch class is an invariant of a singularity germ. The singularities of toric varieties and Schubert varieties are of special interest. We prove certain positivity results for simplicial toric varieties. The positivity for Schubert varieties is illustrated by many examples, but it remains mysterious.

This is a preview of subscription content, access via your institution.

Notes

  1. The original formulation of the localization theorem is stronger. Here we apply it for the localization in the dimension ideal. For an arbitrary prime ideal \(\mathfrak {p}\subset K_\mathbb {T}(pt)=Rep(\mathbb {T})\) there is a maximal group \(H\subset \mathbb {T}\), such that \(K_\mathbb {T}(X)_{\mathfrak {p}}\mathop {\rightarrow }\limits ^{\sim }K_\mathbb {T}(X^H)_{\mathfrak {p}}\). For a smaller ideal \(\mathfrak {p}\) we have to take a smaller subgroup H.

  2. I thank Oleg Karpenkov for driving my attention to this method of summation.

References

  1. Atiyah, M.F., Bott, R.: The moment map and equivariant cohomology. Topology 23, 1–28 (1984)

    Article  MathSciNet  MATH  Google Scholar 

  2. Arapura, D., Bakhtary, P., Włodarczyk, J.: Weights on cohomology, invariants of singularities, and dual complexes. Math. Ann. 357(2), 513–550 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  3. Allday, Christopher, Franz, Matthias, Puppe, Volker: Equivariant cohomology, syzygies and orbit structure. Trans. Am. Math. Soc. 366(12), 6567–6589 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  4. Anderson, D., Griffeth, S., Miller, E.: Positivity and Kleiman transversality in equivariant \(K\)-theory of homogeneous spaces. J. Eur. Math. Soc. (JEMS) 13(1), 57–84 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  5. Paolo, A.: Differential forms with logarithmic poles and Chern–Schwartz–MacPherson classes of singular varieties. C. R. Acad. Sci. Paris Sér. I Math. 329(7), 619–624 (1999)

    Article  MathSciNet  Google Scholar 

  6. Aluffi, P., Constantin Mihalcea, L.: Chern classes of Schubert cells and varieties. J. Algebraic Geom. 18(1), 63–100 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  7. Aluffi, P., Marcolli, M.: Algebro-geometric Feynman rules. Int. J. Geom. Methods Mod. Phys. 8(1), 203–237 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  8. Atiyah, M.F., Segal, G.B.: Equivariant \(K\)-theory and completion. J. Diff. Geom. 3, 1–18 (1969)

    MathSciNet  MATH  Google Scholar 

  9. Baum, P.: Fixed point formula for singular varieties. In: Current trends in algebraic topology, Part 2 (London, ON, 1981), vol. 2 of CMS Conference Proceedngs, pp. 3–22. Am. Math. Soc., Providence, R.I. (1982)

  10. Białynicki-Birula, A.: Some theorems on actions of algebraic groups. Ann. Math. 2(98), 480–497 (1973)

    Article  MathSciNet  MATH  Google Scholar 

  11. Baum, P., Fulton, W., MacPherson, R.: Riemann–Roch for singular varieties. Inst. Hautes Études Sci. Publ. Math. 45, 101–145 (1975)

    Article  MathSciNet  MATH  Google Scholar 

  12. Bernstein, J., Lunts, V.: Equivariant sheaves and functors. Lecture Notes in Mathematics, vol. 1578. Springer-Verlag, Berlin (1994)

    MATH  Google Scholar 

  13. Billey, S., Lakshmibai, V.: Singular loci of Schubert varieties. Progress in Mathematics, vol. 182. Birkhäuser Boston Inc, Boston (2000)

    Book  MATH  Google Scholar 

  14. Borel, A.: Seminar on transformation groups. With contributions by G. Bredon, E. E. Floyd, D. Montgomery, R. Palais. Annals of Mathematics Studies, No. 46. Princeton University Press, Princeton, N.J. (1960)

  15. Brion, M.: Positivity in the Grothendieck group of complex flag varieties. J. Algebra 258(1), 137–159 (2002). Special issue in celebration of Claudio Procesi’s 60th birthday

    Article  MathSciNet  MATH  Google Scholar 

  16. Brasselet, J.-P., Schürmann, J., Yokura, S.: Hirzebruch classes and motivic Chern classes for singular spaces. J. Topol. Anal. 2(1), 1–55 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  17. Berline, N., Vergne, M.: Classes caractéristiques équivariantes. Formule de localisation en cohomologie équivariante. C. R. Acad. Sci. Paris Sér. I Math 295(9), 539–541 (1982)

    MathSciNet  MATH  Google Scholar 

  18. Brion, M., Vergne, M.: An equivariant Riemann–Roch theorem for complete, simplicial toric varieties. J. Reine Angew. Math. 482, 67–92 (1997)

    MathSciNet  MATH  Google Scholar 

  19. Brylinski, J-L, Zhang, B: Equivariant todd classes for toric varieties. Preprint, arXiv:math/0311318, (2003)

  20. Deligne, P.: Théorie de Hodge. II. Inst. Hautes Études Sci. Publ. Math. 40, 5–57 (1971)

    Article  MathSciNet  MATH  Google Scholar 

  21. Edidin, D., Graham, W.: Localization in equivariant intersection theory and the Bott residue formula. Am. J. Math. 120(3), 619–636 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  22. Fulton, W., Johnson, K.: Canonical classes on singular varieties. Manuscr. Math. 32(3–4), 381–389 (1980)

    Article  MathSciNet  MATH  Google Scholar 

  23. Fulton, W.: Introduction to toric varieties. Annals of Mathematics Studies, vol. 131. Princeton University Press, Princeton, NJ (1993)

    Book  Google Scholar 

  24. Fulton, W.: Intersection theory, volume 2 of Ergebnisse der Mathematik und ihrer Grenzgebiete. 3. Folge. A Series of Modern Surveys in Mathematics, 2nd edn. Springer-Verlag, Berlin (1998)

    Google Scholar 

  25. Goresky, M., Kottwitz, R., MacPherson, R.: Equivariant cohomology, Koszul duality, and the localization theorem. Invent. Math. 131(1), 25–83 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  26. Francisco, G., Navarro Aznar, V.: Un critère d’extension des foncteurs définis sur les schémas lisses. Publ. Math. Inst. Hautes Études Sci. 95, 1–91 (2002)

    Article  Google Scholar 

  27. Grothendieck, A.: Formule de Lefschetz (Redige par L. Illusie). Semin. Geom. algebr. Bois-Marie 1965–1966, SGA 5, Lecture Notes on Mathematics 589, Expose No. III, pp. 73–137 (1977)

  28. Hirzebruch, F.: Neue topologische Methoden in der algebraischen Geometrie. Ergebnisse der Mathematik und ihrer Grenzgebiete (N.F.), Heft 9. Springer, Berlin (1956)

    Book  Google Scholar 

  29. Huh, J.: Positivity of chern classes of schubert cells and varieties. Preprint, arXiv:1302.5852 (2013)

  30. Kovács, Sándor J.: Rational, log canonical, Du Bois singularities: on the conjectures of Kollár and Steenbrink. Compos. Math. 118(2), 123–133 (1999)

    Article  MATH  Google Scholar 

  31. Maxim, L., Schürmann, J.: Characteristic classes of singular toric varieties. Communications on Pure and Applied Mathematics, to appear( arXiv:1303.4454) (2014)

  32. Maxim, L., Saito, M., Schürmann, J.: Hirzebruch–Milnor classes of complete intersections. Adv. Math. 241, 220–245 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  33. Musin, O.R.: On rigid Hirzebruch genera. Mosc. Math. J. 11(1), 139–147 (2011). 182

    MathSciNet  MATH  Google Scholar 

  34. Mikosz, M., Weber, A.: Equivariant Hirzebruch class for quadratic cones via degenerations. J. Singul. 12, 131–140 (2015)

    MathSciNet  MATH  Google Scholar 

  35. Oda, T.: Convex bodies and algebraic geometry, volume 15 of Ergebnisse der Mathematik und ihrer Grenzgebiete (3) [Results in Mathematics and Related Areas (3)]. Springer-Verlag, Berlin, 1988. An introduction to the theory of toric varieties, Translated from the Japanese

  36. Ohmoto, T.: Equivariant Chern classes of singular algebraic varieties with group actions. Math. Proc. Camb. Philos. Soc. 140(1), 115–134 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  37. Parusiński, A.: A generalization of the Milnor number. Math. Ann. 281(2), 247–254 (1988)

    Article  MathSciNet  MATH  Google Scholar 

  38. Pragacz, P., Weber, A.: Thom polynomials of invariant cones, Schur functions and positivity. In: Algebraic cycles, sheaves, shtukas, and moduli, Trends Math., pp. 117–129. Birkhäuser, Basel (2008)

  39. Quillen, D.: The spectrum of an equivariant cohomology ring. I. Ann. of Math. (2) 94, 549–572 (1971)

    Article  MathSciNet  MATH  Google Scholar 

  40. Ramanathan, A.: Schubert varieties are arithmetically Cohen–Macaulay. Invent. Math. 80(2), 283–294 (1985)

    Article  MathSciNet  MATH  Google Scholar 

  41. Schwede, K.: A simple characterization of Du Bois singularities. Compos. Math. 143(4), 813–828 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  42. Schürmann, J.: Characteristic classes of mixed Hodge modules. In: Topology of stratified spaces, volume 58 of Mathematical Sciences Research Institute Publications, pp. 419–470. Cambridge University Press, Cambridge (2011)

  43. Segal, G.: Equivariant \(K\)-theory. Inst. Hautes Études Sci. Publ. Math. 34, 129–151 (1968)

    Article  MathSciNet  MATH  Google Scholar 

  44. Totaro, B.: The elliptic genus of a singular variety. Elliptic cohomology, volume 342 of London Mathematical Society Lecture Note Series, pp. 360–364. Cambridge University Press, Cambridge (2007)

    MATH  Google Scholar 

  45. Weber, A.: Equivariant Chern classes and localization theorem. J. Singul. 5, 153–176 (2012)

    MathSciNet  MATH  Google Scholar 

  46. Weber, A.: Computing equivariant characteristic classes of singular varieties. RIMS Kokyuroku 109–129, 2013 (1868)

    Google Scholar 

  47. Weber, A.: Hirzebruch class and Białynicki–Birula decomposition. Preprint, arXiv:1411.6594 (2014)

  48. Woo, A., Yong, A.: Governing singularities of Schubert varieties. J. Algebra 320(2), 495–520 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  49. Yokura, S.: A generalized Grothendieck–Riemann–Roch theorem for Hirzebruch’s \(\chi _y\)-characteristic and \(T_y\)-characteristic. Publ. Res. Inst. Math. Sci. 30(4), 603–610 (1994)

    Article  MathSciNet  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Andrzej Weber.

Additional information

Supported by NCN Grant 2013/08/A/ST1/00804.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Weber, A. Equivariant Hirzebruch class for singular varieties. Sel. Math. New Ser. 22, 1413–1454 (2016). https://doi.org/10.1007/s00029-015-0214-x

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00029-015-0214-x

Keywords

  • Characteristic classes of singular varieties
  • Hirzebruch class
  • Equivariant cohomology
  • Toric varieties
  • Schubert varieties

Mathematics Subject Classification

  • 14C17
  • 14E15
  • 14F43
  • 19L47
  • 55N91
  • 14M25
  • 14M15