On a symplectic generalization of a Hirzebruch problem
Abstract: Motivated by a problem of Hirzebruch, we study $8$-dimensional, closed, symplectic manifolds having a Hamiltonian torus action with isolated fixed points and second Betti number equal to $1$. Such manifolds are automatically positive monotone. Our main result concerns those endowed with a Hamiltonian $T2$-action and fourth Betti number equal to $2$. We classify their isotropy data, (equivariant) cohomology rings and (equivariant) Chern classes, and prove that they agree with those of certain explicit Fano $4$-folds with torus actions. Moreover, under more general assumptions, we prove several finiteness results concerning Betti and Chern numbers of $8$-dimensional, positive monotone symplectic manifolds with a Hamiltonian torus action.
- K. Ahara and A. Hattori. 4444-dimensional symplectic S1superscript𝑆1S^{1}italic_S start_POSTSUPERSCRIPT 1 end_POSTSUPERSCRIPT-manifolds admitting moment map. J. Fac. Sci. Univ. Tokyo Sect. IA Math., 38(2):251–298, 1991.
- M. F. Atiyah and R. Bott. The moment map and equivariant cohomology. Topology, 23(1):1–28, 1984.
- Classes caractéristiques équivariantes. Formule de localisation en cohomologie équivariante. C. R. Acad. Sci. Paris Sér. I Math., 295(9):539–541, 1982.
- A. Bialynicki-Birula. Some theorems on actions of algebraic groups. Ann. of Math. (2), 98:480–497, 1973.
- M. Brion. Some structure theorems for algebraic groups. In Algebraic groups: structure and actions, volume 94 of Proc. Sympos. Pure Math., pages 53–126. Amer. Math. Soc., Providence, RI, 2017.
- I. Charton. Toric one-skeletons for complexity-one spaces. arXiv, 2001.11386, 2020.
- I. Charton. Tall and monotone complexity one spaces of dimension six. PhD Thesis, Cologne, 2021.
- I. Charton and L. Kessler. Monotone symplectic six-manifolds that admit a hamiltonian gkm action are diffeomorphic to smooth fano threefolds. arXiv, 2308.10541v2, 2023.
- Compact monotone tall complexity one T𝑇{T}italic_T-spaces. arXiv, 2307.04198, 2023.
- Y. Cho and M. K. Kim. Unimodality of the Betti numbers for Hamiltonian circle action with isolated fixed points. Math. Res. Lett., 21(4):691–696, 2014.
- J. Fine and D. Panov. Hyperbolic geometry and non-Kähler manifolds with trivial canonical bundle. Geom. Topol., 14(3):1723–1763, 2010.
- Circle-invariant fat bundles and symplectic Fano 6-manifolds. J. Lond. Math. Soc. (2), 91(3):709–730, 2015.
- M. Furushima. Complex analytic compactifications of 𝐂3superscript𝐂3{\bf C}^{3}bold_C start_POSTSUPERSCRIPT 3 end_POSTSUPERSCRIPT. volume 76, pages 163–196. 1990. Algebraic geometry (Berlin, 1988).
- M. Furushima. The complete classification of compactifications of 𝐂3superscript𝐂3{\bf C}^{3}bold_C start_POSTSUPERSCRIPT 3 end_POSTSUPERSCRIPT which are projective manifolds with the second Betti number one. Math. Ann., 297(4):627–662, 1993.
- L. Godinho and S. Sabatini. New tools for classifying Hamiltonian circle actions with isolated fixed points. Found. Comput. Math., 14(4):791–860, 2014.
- 12, 24 and beyond. Adv. Math., 319:472–521, 2017.
- O. Goertsches and L. Zoller. Reconstructing the orbit type stratification of a torus action from its equivarant cohomology. J. Algebraic Combin., 56(3):799–822, 2022.
- R. F. Goldin and S. Tolman. Towards generalizing Schubert calculus in the symplectic category. J. Symplectic Geom., 7(4):449–473, 2009.
- Equivariant cohomology, Koszul duality, and the localization theorem. Invent. Math., 131(1):25–83, 1998.
- Polynomial assignments. Indag. Math. (N.S.), 25(5):992–1018, 2014.
- A GKM description of the equivariant cohomology ring of a homogeneous space. J. Algebraic Combin., 23(1):21–41, 2006.
- V. Guillemin and C. Zara. Combinatorial formulas for products of Thom classes. In Geometry, mechanics, and dynamics, pages 363–405. Springer, New York, 2002.
- M. Harada and G. D. Landweber. Surjectivity for Hamiltonian G𝐺Gitalic_G-spaces in K𝐾Kitalic_K-theory. Trans. Amer. Math. Soc., 359(12):6001–6025, 2007.
- A. Hattori. S1superscript𝑆1S^{1}italic_S start_POSTSUPERSCRIPT 1 end_POSTSUPERSCRIPT-actions on unitary manifolds and quasi-ample line bundles. J. Fac. Sci. Univ. Tokyo Sect. IA Math., 31(3):433–486, 1985.
- Manifolds and modular forms, volume E20 of Aspects of Mathematics. Friedr. Vieweg & Sohn, Braunschweig, 1992. With appendices by Nils-Peter Skoruppa and by Paul Baum.
- F. Hirzebruch. Some problems on differentiable and complex manifolds. Ann. of Math. (2), 60:213–236, 1954.
- D. Jang. Almost complex torus manifolds—graphs and Hirzebruch genera. Int. Math. Res. Not. IMRN, (17):14594–14609, 2023.
- D. Jang and S. Tolman. Hamiltonian circle actions on eight-dimensional manifolds with minimal fixed sets. Transform. Groups, 22(2):353–359, 2017.
- Hamiltonian circle actions on symplectic manifolds and the signature. J. Geom. Phys., 23(3-4):301–307, 1997.
- Yael Karshon. Periodic Hamiltonian flows on four-dimensional manifolds. Mem. Amer. Math. Soc., 141(672):viii+71, 1999.
- F. C. Kirwan. Cohomology of quotients in symplectic and algebraic geometry, volume 31 of Mathematical Notes. Princeton University Press, Princeton, NJ, 1984.
- D. N. Lehmer. Dickson’s history of the theory of numbers. Bull. Amer. Math. Soc., 26(6):281, 1920.
- N. Lindsay. Hamiltonian circle actions on complete intersections. Bull. Lond. Math. Soc., 54(1):206–212, 2022.
- N. Lindsay and D. Panov. S1superscript𝑆1S^{1}italic_S start_POSTSUPERSCRIPT 1 end_POSTSUPERSCRIPT-invariant symplectic hypersurfaces in dimension 6 and the Fano condition. J. Topol., 12(1):221–285, 2019.
- J. Milnor and D. Husemoller. Symmetric bilinear forms, volume Band 73 of Ergebnisse der Mathematik und ihrer Grenzgebiete [Results in Mathematics and Related Areas]. Springer-Verlag, New York-Heidelberg, 1973.
- T. Peternell and M. Schneider. Compactifications of 𝐂3superscript𝐂3{\bf C}^{3}bold_C start_POSTSUPERSCRIPT 3 end_POSTSUPERSCRIPT. I. Math. Ann., 280(1):129–146, 1988.
- Y. Prokhorov and M. Zaidenberg. Examples of cylindrical Fano fourfolds. Eur. J. Math., 2(1):262–282, 2016.
- Y. Prokhorov and M. Zaidenberg. Fano-Mukai fourfolds of genus 10 as compactifications of ℂ4superscriptℂ4\mathbb{C}^{4}blackboard_C start_POSTSUPERSCRIPT 4 end_POSTSUPERSCRIPT. Eur. J. Math., 4(3):1197–1263, 2018.
- Y. G. Prokhorov. Fano threefolds of genus 12121212 and compactifications of 𝐂3superscript𝐂3{\bf C}^{3}bold_C start_POSTSUPERSCRIPT 3 end_POSTSUPERSCRIPT. Algebra i Analiz, 3(4):162–170, 1991.
- Y. G. Prokhorov. Compactifications of 𝐂4superscript𝐂4{\bf C}^{4}bold_C start_POSTSUPERSCRIPT 4 end_POSTSUPERSCRIPT of index 3333. In Algebraic geometry and its applications (Yaroslavlc, 1992), volume E25 of Aspects Math., pages 159–169. Friedr. Vieweg, Braunschweig, 1994.
- S. Sabatini. On the Chern numbers and the Hilbert polynomial of an almost complex manifold with a circle action. Commun. Contemp. Math., 19(4):1750043, 51, 2017.
- S. Sabatini and S. Tolman. New techniques for obtaining Schubert-type formulas for Hamiltonian manifolds. J. Symplectic Geom., 11(2):179–230, 2013.
- S. Tolman. On a symplectic generalization of petrie’s conjecture. Trans. Amer. Math. Soc., 362(8):3963–3996, 2010.
Paper Prompts
Sign up for free to create and run prompts on this paper using GPT-5.
Top Community Prompts
Collections
Sign up for free to add this paper to one or more collections.