TOPICS IN LOCALLY CONFORMALLY KÄHLER GEOMETRY

Program PNCDI III, Project number PN-III-P4-ID-PCE-2016-0065, Contract number 8/12.07.2017


Financed by Romanian Ministry of Research and Innovation, CNCS - UEFISCDI

Project Executive Summary

Locally conformally Kähler (LCK) geometry is concerned with complex manifolds of complex dimension at least two admitting a Kähler covering with deck transformations acting by holomorphic homotheties with respect to the Kähler metric. Forgetting the complex structure we obtain Locally Conformally Symplectic (LCS) manifolds. The passage between LCS and LCK settings is both directions. Almost all known non-Kähler compact surfaces are LCK. In higher dimensions, we have Hopf manifolds, Oeljeklaus-Toma (OT) manifolds, and their complex submanifolds (when they do exist).
Objectives:

1. Classification of surjective holomorphic maps from (compact) LCK manifolds. The total space, together with natural conditions on the fibre, should put restrictions on the Hermitian structure of the base.

2. Proving the non-existence of LCK metrics on OT manifolds with t>1.

3. OT manifolds do not have curves and surfaces, and the LCK ones do not have subvarieties at all. We want to prove that if a compact complex submanifold exists in an OT manifold, it must be an OT manifold itself. The problem can be translated into one concerning holomorphic bundles.

4. Studying holomorphic vector bundles (stability, filtrability) of small rank on OT.

5. Initiating the systematic study of complex LCS manifolds, relations with other geometries.

6. Classification of toric LCS manifolds. We expect a statement of this kind: toric, compact LCS manifolds should be LCK and indeed Vaisman.

7. Study of the spectral sequence associated to the canonical foliation of a Vaisman manifold and computing the dimensions of its terms. This will obstruct a given 2-dimensional foliation on a compact complex manifold to come from a Vaisman structure.

8. Study of indefinite LCK manifolds and of their submanifolds, in particular of semi-Riemannian submersions from indefinite LCK manifolds, with focus on statistical manifolds.

9. Studying particular functionals of Yang-Mills type on LCK and Vaisman manifolds.

Research team:

  • Liviu Ornea (Project Leader)
  • Florin Belgun (Experienced Researcher)
  • Sorin Dăscălescu (Experienced Researcher)
  • Catalin Gherghe (Experienced Researcher)
  • Alexandra Otiman (PhD Student)
  • Vladimir Slesar (Experienced Researcher)
  • Miron Stanciu (PhD Student)
  • Gabriel-Eduard Vîlcu (Experienced Researcher)
  • Victor-Corneliu Vuletescu (Experienced Researcher)

  • Budget



    Reports:

    2017:

    Financial report

    Scientific report


    Research funded by this grant:

    A. Articles published in ISI ranked journals

    A1. S. Dăscălescu, C. Năstăsescu, L. Năstăsescu: Graded semisimple algebras are symmetric, Journal of Algebra 491 (2017), 207-218.

    A2. V. Slesar, M. Visinescu, G.E. Vîlcu: Hidden symmetries in Sasaki–Einstein geometries, Physics of Atomic Nuclei 80(4) (2017), pp 801–807.

    A3. L. Ornea, V. Slesar: The spectral sequence of the canonical foliation of a Vaisman manifold, Annals of Global Analysis and Geometry 53(3) (2018), pp 311–329.

    A4. A.D. Vîlcu, G.E. Vîlcu: An algorithm to estimate the vertices of a tetrahedron from uniform random points inside, Annali di Matematica Pura ed Applicata 197(2) (2018), pp 487–500.

    A5. A. Moroianu, S. Moroianu, L. Ornea: Locally conformally Kähler manifolds with holomorphic Lee field, Differential Geometry and its Applications 60 (2018), 33-38.

    A6. G.E. Vîlcu: An optimal inequality for Lagrangian submanifolds in complex space forms involving Casorati curvature, Journal of Mathematical Analysis and Applications 465 (2018), no. 2, 1209–1222.

    A7. L. Ornea, M. Verbitsky, V. Vuletescu: Flat affine subvarieties in Oeljeklaus-Toma manifolds, Mathematische Zeitschrift (2018), accepted.

    A8. F. Beşleagă, S. Dăscălescu, L. Van Wyk: Classifying good gradings on structural matrix algebras, Linear and Multilinear Algebra (2018), accepted.

    A9. L. Ornea, M. Verbitsky: Positivity of LCK potential, Journal of Geometric Analysis (2018), accepted.

    B. Papers submitted and preprints


    B1. N. Istrati, A. Otiman: De Rham and twisted cohomology of Oeljeklaus-Toma manifolds, submitted (2017).

    B2. C. Gherghe: On a Yang-Mills type functional, submitted (2017).

    B3. F. Belgun, O. Goertsches, D. Petrecca: Locally conformally symplectic convexity, submitted (2018).

    Last update: 14.05.2018