Selected publications

A. Research Articles

Preprints

Balanced metrics and Gauduchon cone of locally conformally Kahler manifolds (in collaboration with Misha Verbitsky).

Holomorphic tensors on Vaisman manifolds (in collaboration with Misha Verbitsky).

A Calabi-Yau theorem on Vaisman manifolds (in collaboration with Misha Verbitsky). To appear in Communications in Analysis and geometry, 32 (10) (2024).

Mall bundles and flat connections on Hopf manifolds (in collaboration with Misha Verbitsky). To appear in Annales de l'Inst. Fourier. https://aif.centre-mersenne.org/item/10.5802/aif.3647.pdf

Conformal foliations, Kähler twists and the Weinstein construction (in collaboration with Paul-Andi Nagy).

Homogeneous locally conformally Kähler manifolds (in collaboration with Andrei Moroianu) arXiv:1311.0671

Published papers

On the Preeminence of Euclidean Geometry: Nash's Embedding Theorems (in collaboration with Mircea Dumitru). Journal for General Philosophy of Science (2024) https://doi.org/10.1007/s10838-024-09684-7.

Algebraic cones of LCK manifolds with potential (in collaboration with Misha Verbitsky). Journal of Geometry and Physics 198 (2024) 105103. https://doi.org/10.1016/j.geomphys.2024.105103.

Lee classes on LCK manifolds with potential (in collaboration with Misha Verbitsky). Tohoku Math. Journal 76 no. 1 (2024), 105-125.

Bimeromorphic geometry of LCK manifolds (in collaboration with Misha Verbitsky). Proceedings Amer. Math. Soc. 152 (2024), 701-707. https://doi.org/10.1090/proc/16559

Do products of compact complex manifolds admit LCK metrics? (in collaboration with Misha Verbitsky and Victor Vuletescu). Bulletin of the London Math. Soc. 56 (2024), 756-766.

Non-linear Hopf manifolds are locally conformally Kähler (in collaboration with Misha Verbitsky). Journal of Geometric Analysis, Volume 33 (2023), article number 201, https://doi.org/10.1007/s12220-023-01273-2

Compatibility between non-Kähler structures on complex (nil)manifolds (in collaboration with Alexandra Otiman and Miron Stanciu). Transformations groups, 28 (2023), 1669-1686.

Supersymmetry and Hodge theory on Sasakian and Vaisman manifolds (in collaboration with Misha Verbitsky). Manuscripta Mathematica 170 (2023), 629-658.

Deformations of Vaisman manifolds (in collaboration with Vladimir Slesar). Differential Geometry and its Applications, 85 (2022), 101940. https://doi.org/10.1016/j.difgeo.2022.101940

Compact homogeneous locally conformally Kähler manifolds are Vaisman. A new proof (in collaboration with Misha Verbitsky). Rivista Matematica dell'Università di Parma, Volume 13 (2022) no. 2, 439-448. - Proceedings of the meeting Cohomology of Complex Manifolds and Special Structures II Levico Terme (Trento), July 5-9, 2021.

Twisted Dolbeault cohomology of nilpotent Lie algebras (in collaboration with Misha Verbitsky). Transformation Groups, 27 (2022), 225-238

Classification of non-Kahler surfaces and locally conformally Kahler geometry (in collaboration with Misha Verbitsky and Victor Vuletescu). Russian Math. Surveys (Uspekhi Mat. Nauk) 76 (2021), 261-289. https://doi.org/10.1070/RMS9858

Closed orbits of Reeb fields on Sasakian manifolds and elliptic curves on Vaisman manifolds (in collaboration with Misha Verbitsky). Mathematische Zeitschrift 299 (2021), 1187-2296. https://doi.org/10.1007/s00209-021-02776-w

Hopf surfaces in locally conformally Kähler manifolds with potential (in collaboration with Misha Verbitsky). Geometriae Dedicata 207 (2020), 219-226. https://doi.org/10.1007/s10711-019-00495-5.

A characterization of compact locally conformally hyperkähler manifolds (in collaboration with Alexandra Otiman). Annali di Matematica Pura ed Applicata 198 (2019). 1541-1549. https://doi.org/10.1007/s10231-019-00829-w

Flat affine subvarieties in Oeljeklaus-Toma manifolds (in collaboration with Misha Verbitsky and Victor Vuletescu). Mathematische Zeitschrift 292 (2019). 839-847. https://doi.org/10.1007/s00209-018-2121-2

Positivity of LCK potential (in collaboration with Misha Verbitsky). Journal of Geometric Analysis 29 (2019), 1479-1489. https://doi.org/10.1007/s12220-018-0046-y

Locally conformally Kähler manifolds with holomorphic Lee field (in collaboration with Andrei Moroianu and Sergiu Moroianu) Diff. Geom. Appl., 60 (2018), 33--38.

The spectral sequence of the canonical foliation of a Vaisman manifold (in collaboration with Vladimir Slesar). Annals of Global Analysis and Geometry, 53 (3), (2018), 311--329.

Weighted Bott-Chern and Dolbeault cohomology for LCK manifolds with potential (in collaboration with Misha Verbitsky and Victor Vuletescu). J. Math. Soc. Japan 70 (2018), nr. 1, 407--420.

Embedding of LCK manifolds with potential into Hopf manifolds using Riesz-Schauder theorem (in collaboration with Misha Verbitsky). In "Complex and Symplectic Geometry", Springer INdAM serie, 2017, 137--148.

Basic Morse-Novikov cohomology for foliations (in collaboration with Vladimir Slesar), Mathematische Zeitschrift 284 (2016), no. 1-2, 469-489.

LCK rank of locally conformally Kähler manifolds with potential (in collaboration with Misha Verbitsky). J. Geom. Physics. 107 (2016), 92-98.

Locally conformally Kähler metrics obtained from pseudoconvex shells (in collaboration with Misha Verbitsky) Proceedings Amer. Math. Soc. 144 (2016), 325-335.

Compact homogeneous LCK manifolds are Vaisman (in collaboration with Andrei Moroianu and P. Gauduchon) Math. Annalen. 361 (2015), 1043-1048.

Holomorphic submersions of locally conformally Kähler manifolds (in collaboration with Maurizio Parton and V. Vuletescu). Annali di Matematica Pura ed Applicata 193(5) (2014), 1345-1351.

Oeljeklaus-Toma manifolds and locally conformally Kahler metrics. A state of the art. (in collaboration with V. Vuletescu). Stud. Univ. Babes-Bolyai Math. 58(2013), No. 4, 459-468.

Spin(9) geometry of the octonionic Hopf fibration (in collaboration with M. Parton, P. Piccinni, V. Vuletescu). Transformation groups, 18 nr. 3 (2013) 845-864. DOI: 10.1007/S00031-013-9233-x.

Blow-ups of locally conformally Kähler manifolds (in collaboration with Misha Verbitsky and Victor Vuletescu, International Mathematics Research Notices 12 (2013) 2809-2821. doi:10.1093/imrn/rns128.

Locally conformally Kähler manifolds admitting a holomorphic conformal flow (in collaboration with Misha Verbitsky), Math. Zeitschrift 273 (2013), 605-611. DOI 10.1007/s00209-012-1022-z.

An integral invariant from the viewpoint of locally conformally Kähler geometry (in collaboration with A. Futaki and K. Hattori), arXiv:1105.4774. Manuscripta mathematica, 140, 1-12 (2013). DOI: 10.1007/s00229-011-0527-9

Submanifolds in manifolds with metric mixed 3-structures (in collaboration with S. Ianus and G.E. Vilcu). Mediterranean Journal of Math. 9(2012), 105-128.

Twistor theory for CR quaternionic manifolds and related structures (in collaboration with S. Marchiafava and R. Pantilie, arXiv:0905.1455. Monatshefte fuer Mathematik. 167 (2012), 531-545.

Automorphisms of locally conformally Kähler manifolds (in collaboration with M. Verbitsky), arXiv:0906.2836. International Mathematics Research Notices vol. 2012 Nr. 4 894-903 doi:10.1093/imrn/rnr053.

Oeljeklaus-Toma manifolds admitting no complex subvarieties (in collaboration with Misha Verbitsky), Mathematical Research Letters 18(4), (2011), 747-754.

A report on locally conformally Kähler manifolds (in collaboration with Misha Verbitsky), arxiv:1002.3473. "Harmonic Maps and Differential Geometry" Contemporary Mathematics 542, 135-150, 2011.

On holomorphic maps and generalized complex geometry (in collaboration with R. Pantilie). Journal of Geometry and Physics 61 (2011) 1502-1515, doi: 10.1016/j.geomphys.2011.03.017.

Remarks on the product of harmonic forms (in collaboration with Mihaela Pilca ), arXiv:1001.2129 Pacific Journal of Mathematics, 250 (2011), 353-363.

Essential points of conformal vector fields (in collaboration with F.A. Belgun and Andrei Moroianu ), arXiv:1002.0482. Journal of Geometry and Physics 61 (2011), 589-593.

Twistorial maps between quaternionic manifolds (in collaboration with S. Ianus, S. Marchiafava, R. Pantilie). Annali Scuola Normale Superiore di Pisa, Cl. Sci. (5) Vol. IX (2010), 47-67.

Locally conformal Kähler manifolds with potential (in collaboration with Misha Verbitsky), Mathematische Annalen 348 (2010), 25-33.

Topology of locally conformal Kähler manifolds with potential (in collaboration with Misha Verbitsky). International Mathematics Research Notices, 4 (2010), 117-126. MR:2011e:32021

On the local structure of generalized Kähler manifolds (in collaboration with R. Pantilie), Bull. Math. Soc. Sci. Math. Roumanie, 52(2009), 347-354. MR 2554493

Transformations of locally conformally Kähler manifolds (in collaboration with Andrei Moroianu ), Manuscripta Mathematica 130 (2009), 93-100. MR 2010f:53046.

Morse-Novikov cohomology of locally conformally Kähler manifolds (in collaboration with Misha Verbitsky), Journal of Geometry and Physics 59, No. 3 (2009), 295-305. MR 2010h:32024.

Einstein-Weyl structures on complex manifolds and conformal version of Monge-Ampere equation (in collaboration with Misha Verbitsky), Bull. Math. Soc. Sci. Math. Roumanie Tome 51(99) No. 4, 2008, 339-353. MR 2010a:32039

Conformally Einstein Products and Nearly Kähler Manifolds (in collaboration with Andrei Moroianu ), Annals of Global Analysis and Geometry 33(2008), 11-18. MR 2008i:53058

Constructions in Sasakian Geometry (in collaboration with Charles P. Boyer, Krzysztof Galicki). Mathematische Zeitschrift 257 (2007), 907-924. MR 2008m:53103

Sasakian structures on CR-manifolds (in collaboration with Misha Verbitsky), Geometriae Dedicata, 125 (2007), 159-173. MR 2008h:53071

Embeddings of compact Sasakian manifolds (in collaboration with Misha Verbitsky), Mathematical Research Letters, 14 (2007), 703-710. MR 2008c:53038

Reduction of Vaisman structures in complex and quaternionic geometry (in collaboration with R. Gini, M. Parton and P. Piccinni), Journal of Geometry and Physics, 56 (2006), 2501-2522. MR 2007i:53080.

CR-submanifolds. A class of examples. Revue roumaine de math. pures appl. 51 (2006) 77-85. MR 2007i:53057.

Locally conformally Kähler manifolds. A selection of results. Lecture Notes of Seminario Interdisciplinare di Matematica, 4(2005), 121-152. MR 2007c:53101. For an updated version see math.DG/0411503.

Non-zero contact and Sasakian reduction (in collaboration with O. Dr\u agulete), Differential Geometry and its Applications 24 (2006), 260-270. MR 2007e:53111.

Harmonicity and minimality of vector fields and distributions on locally conformal Kähler and hyperkähler manifolds (in collaboration with L. Vanhecke), Bull. of the Belgian Math. Soc. "Simon Stevin" 12 (2005) 543-555. MR 2007d:53106

An immersion theorem for Vaisman manifolds (in collaboration with Misha Verbitsky,), Mathematische Annalen 332 (2005), 121-143. MR 2006e:53112

Locally conformal Kähler reduction (in collaboration with R. Gini and M. Parton,). Journal für die Reine und Angewandte Mathematik 581 (2005), 1-21. MR 2006c:53077

Geometric flow on compact locally conformally Kähler manifolds (in collaboration with Y. Kamishima ). Tohoku Math. J. 57 (2) (2005), 201-221. MR 2006g:53112

Eigenvalue estimates for the Dirac operator and harmonic 1-forms of constant length (in collaboration with A. Moroianu). Comptes Rendus Acad. Sci. Paris, 338 (2004), 561-564. MR 2005f:58054

Structure theorem for compact Vaisman manifolds, Mathematical Research Letters, 10 (2003), 799-805 (in collaboration with Misha Verbitsky). Also available at math.DG/0305259. MR 2004j:53093)

Potential 1-forms for hyper-Kähler structures with torsion, Classical and Quantum Gravity 20 (2003), 1845-1856 (in collaboration with Y.S Poon and A. Swann). MR 2004e:53070

Cosphere bundle reduction in contact geometry, Journal of Symplectic Geometry, 1(4) (2002), 695-714. (in collaboration with O. Dragulete and T.S. Ratiu) MR 2004m:53141.

Weyl structures in quaternionic geometry. A state of the art. Barletta, Elisabetta (ed.), Selected topics in geometry and mathematical physics. Vol. I. Potenza: Univ. degli Studi della Basilicata, Dipartimento di Matematica, Seminario Interdisciplinare di Matematica, 43-80 (2001). Also on math.DG/0105041. Zbl 1029.53055

Cayley 4-frames and a quaternion Kähler reduction related to Spin(7), Global differential geometry: the mathematical legacy of Alfred Gray (Bilbao 2000), 401-405, Contemporary Mathematics 288, Amer. Math. Soc. Providence, RI, 2001 (in collaboration with Paolo Piccinni). MR 2003c:53072

Reduction of Sasakian manifolds, Journal of Mathematical Physics 48 (2001), 3809-3816 (in collaboration with G. Grantcharov) MR 2002e:53060

Local almost contact metric 3-structures Publicationes Mathematicae (Debrecen) 57 (2000) 499-508 (in collaboration with Paola Matzeu) MR 2002a:53057

Complex structures on some Stiefel manifolds, Bull. Math. Soc. Sci. Math. Roumanie (N.S.) 49 (2000) (in collaboration with Paolo Piccinni) MR 2002c:53120

On some moment maps and induced Hopf bundles in the quaternionic projective space, International Journal of Mathematics 11 (2000), 925-942 (in collaboration with Paolo Piccinni) MR 2002a:53061

Intersections of Riemannian submanifolds. Variations on a theme by T. J. Frankel, Rendiconti di Matematica (Roma), 19 (1999), 107-121 (in collaboration with T. Bingh and L. Tamassy) MR 2000g:53074

Locally conformal Kähler metrics on Hopf surfaces, Annales de l'Institut Fourier, 48 (1998), 1107-1127 (in collaboration with P. Gauduchon) MR 2000g:53088

Compact hyperhermitian-Weyl and quaternion Hermitian-Weyl manifolds, Annals of Global Analysis and Geometry, 16 (1998), 383-398. (in collaboration with P. Piccinni). MR 99k:53097; Erratum, Same journal, 18 (2000), 105-106. MR 2000k:53044.

An example of an almost hyperbolic Hermitian manifold, International Journal of Mathematics and Mathematical Sciences, 21 (1998), 613-618 (in collaboration with C.-L. Bejan). MR 98m:53039

Locally conformal Kähler structures in quaternionic geometry, Transactions of the American Mathematical Society, 349 (1997), 641-655, (in collaboration with P. Piccinni). MR 97e:53091.

Induced Hopf bundles and Einstein metrics, in New developments in differential geometry, Budapest (1996), 295-306, Kluwer (in collaboration with P. Piccinni). MR 99k:53099.

Weyl structures on quaternionic manifolds, Proceedings of the Meeting on Quaternionic Structures in Mathematics and Physics, Trieste 1994. SISSA, Trieste, (1996), 261-267, (in collaboration with P. Piccinni). MR 99k:53098.

Holomorphic and harmonic maps on locally conformal Kähler manifolds, Bolletino dell'Unione Matematica Italiana, (7)9-A(1995), 569-579, (in collaboration with S. Ianus, V. Vuletescu), MR 96i:58037

Conformal geometry of Riemannian submanifolds. Gauss, Codazzi and Ricci equations, Rendiconti di Matematica (Roma), 15, (1995), 233-249, (in collaboration with G. Romani). Zbl. 833:53015.

Locally conformal Kähler manifolds. A survey, Quaderno n. 12, Dip. di Mat., Univ. di Roma "La Sapienza", (1994)

The fundamental equations of conformal submersions, Beiträge zur Algebra und Geometrie / Contributions to Algebra and Geometry, 34, (1993), 233-243, (in collaboration with G. Romani), MR 95a:53055

Submanifolds with parallel second fundamental form in a generalized Hopf manifold, Ricerche di Matematica (Napoli), XLII, (1993), 3-9, MR 95d:35066

Immersions spheriques dans une variete de Hopf generalisee, Comptes Rendus de l' Acad. Sci. Paris, 316, Serie I, (1993), 63-66, (in collaboration with S. Ianus, K. Matsumoto), MR 93m:53067

A theorem on nonnegatively curved locally conformal Kähler manifolds, Rendiconti di Matematica (Roma), serie VII, 12, (1992), 257-262, MR 93h:53071

A class of antiinvariant submanifolds of a generalized Hopf manifold, Bull. Math. de la Soc. Sci. Math. de Roumanie, 34, (1990), 115-123, (in collaboration with S. Ianus), MR 91m:53039

Minimal real hypersurfaces of a generalized Hopf manifold, Analele St. Univ. "Al. I. Cuza" Iasi, 2, (1990), 137-142, MR 92i:53019

Complex hypersurfaces with planar geodesics in generalized Hopf manifolds, Mathematika Balkanica 3 (1989) 92-96, MR 90g:53072

Complex hypersurfaces of a generalized Hopf manifold, Publications de l'Inst. Math. (Beograd), 42, (1987), 123-129, (in collaboration with S. Ianus, K. Matsumoto) MR 89f:53079

CR-submanifolds of a locally conformal Kähler manifold, Demonstratio Mathematica, 19, (1986), 863-869, MR 90g:53072

B. Monographs

Locally conformal Kähler geometry, Progress in Mathematics 155, Birkhäuser, 1998 (in collaboration with Sorin Dragomir).

Principles of locally conformally Kähler geometry, Progress in Mathematics 354, Birkhäuser, 2024 (in collaboration with Misha Verbitsky). https://arxiv.org/pdf/2208.07188.

C. Textbooks

An introduction in differential geometry (in Romanian), Theta Foundation Publ. House, 2015.

An introduction in geometry (in Romanian, in collaboration with A. Turtoi), Theta Foundation Publ. House, 2000. 2nd edition: 2011.

Differentiable curves and surfaces. A problem book (in Romanian), Univ. of Bucharest Publ. House, 1995.