Abstract
Lagrangian submanifolds, a class of Riemannian submanifolds that arose naturally in the context of Hamiltonian mechanics, play an important role in some modern theories of physics. In this paper, using an optimization technique on submanifolds immersed in Riemannian manifolds, we first obtain some sharp inequalities for \(\delta \)-Casorati curvature invariants of Lagrangian submanifolds in quaternionic space forms, i.e. quaternionic Kähler manifolds of constant q-sectional curvature. Then we show that in the class of Lagrangian submanifolds in quaternionic space forms, there are only two subclasses of ideal Casorati submanifolds, namely the family of totally geodesic submanifolds and a particular subfamily of H-umbilical submanifolds. Finally, we provide some examples to illustrate the obtained results. In particular, we point out that an entire family of ideal Casorati Lagrangian submanifolds can be constructed using the concept of quaternionic extensor introduced by Oh and Kang in the early 2000s.
Similar content being viewed by others
Data Availability
Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.
References
Alegre, P., Chen, B.-Y., Munteanu, M.I.: Riemannian submersions, \(\delta \)-invariants, and optimal inequality. Ann. Glob. Anal. Geom. 42(3), 317–331 (2012)
Alodan, H., Chen, B.-Y., Deshmukh, S., Vîlcu, G.-E.: A generalized Wintgen inequality for quaternionic CR-submanifolds. Rev. R. Acad. Cienc. Exactas Fis. Nat. Ser. A Mat. RACSAM, 114(3), 129 (2020)
Aquib, M., Lee, J.W., Vîlcu, G.-E., Yoon, D.W.: Classification of Casorati ideal Lagrangian submanifolds in complex space forms. Differ. Geom. Appl. 63, 30–49 (2019)
Aquib, M., Shahid M.H.: Generalized normalized \(\delta \)-Casorati curvature for statistical submanifolds in quaternion Kaehler-like statistical space forms. J. Geom. 109, 1, Art. 13, 13 pp (2018)
Brubaker, N., Suceavă, B.: A geometric interpretation of Cauchy-Schwarz inequality in terms of Casorati curvature. Int. Electron. J. Geom. 11(1), 48–51 (2018)
Cannas da Silva, A.: Lectures on symplectic geometry. Lecture Notes in Mathematics, vol. 1764, 2nd edn., Springer, Berlin (2008)
Casorati, F.: Mesure de la courbure des surfaces suivant l’idée commune. Acta Math. 14(1), 95 (1890)
Chen, B.-Y.: Totally umbilical submanifolds of quaternion-space-forms. J. Aust. Math. Soc. 26(2), 154–162 (1978)
Chen, B.-Y.: Some pinching and classification theorems for minimal submanifolds. Arch. Math. 60(6), 568–578 (1993)
Chen, B.-Y.: Complex extensors and Lagrangian submanifolds in complex Euclidean spaces. Tohoku Math. J. 49(2), 277–297 (1997)
Chen, B.-Y.: Interaction of Legendre curves and Lagrangian submanifolds. Israel J. Math. 99(1), 69–108 (1997)
Chen, B.-Y.: Representation of flat Lagrangian H-umbilical submanifolds in complex Euclidean spaces. Tohoku Math. J. 51, 13–20 (1999)
Chen, B.-Y.: Pseudo-Riemannian geometry, \(\delta \)-invariants and applications. World Scientific, Hackensack, NJ (2011)
Chen, B.-Y.: Recent developments in \(\delta \)-Casorati curvature invariants. Turk. J. Math. 45, 1–46 (2021)
Chen, B.-Y., Dillen, F.: Optimal general inequalities for Lagrangian submanifolds in complex space forms. J. Math. Anal. Appl. 379(1), 229–239 (2011)
Chen, B.-Y., Decu, S., Vîlcu, G.-E.: Inequalities for the Casorati curvature of totally real spacelike submanifolds in statistical manifolds of type para-Kähler space forms. Mathematics 23(11), 1399 (2021)
Chen, B.-Y., Prieto-Martin, A., Wang, X.: Lagrangian submanifolds in complex space forms satisfying an improved equality involving \(\delta (2,2)\). Publ. Math. Debrecen 82, 193–217 (2013)
Chen, B.-Y., Yıldırım, H.: Classification of ideal submanifolds of real space forms with type number \(\le \) 2. J. Geom. Phys. 92, 167–180 (2015)
Decu, S., Haesen, S., Verstraelen, L.: Optimal inequalities involving Casorati curvatures. Bull. Transilv. Univ. Brasov Ser. B (NS) 14(49), 85–93 (2007)
Decu, S., Haesen, S., Verstraelen, L.: Optimal inequalities characterising quasi-umbilical submanifolds. J. Inequal. Pure Appl. Math 9(3), 79 (2008)
Decu, S., Haesen, S., Verstraelen, L.: Inequalities for the Casorati curvature of statistical manifolds in holomorphic statistical manifolds of constant holomorphic curvature. Mathematics 8, 251 (2020)
Dillen, F., Fastenakels, J.: On an inequality of Oprea for Lagrangian submanifolds. Cent. Eur. J. Math. 7(1), 140–144 (2009)
Funabashi, S.: Totally complex submanifolds of a quaternionic Kaehlerian manifold. Kodai Math. J. 2(3), 314–336 (1979)
Gentili, G., Marchiafava, S., Pontecorvo, M.: (Eds.) Quaternionic structures in mathematics and physics. In: Proceedings of the Meeting on Quaternionic Structures in Mathematics and Physics, SISSA, Trieste, Italy, September 5-9, (1994)
Haesen, S., Kowalczyk, D., Verstraelen, L.: On the extrinsic principal directions of Riemannian submanifolds. Note Mat. 29(2), 41–53 (2010)
He, G., Liu, H., Zhang, L.: Optimal inequalities for the Casorati curvatures of submanifolds in generalized space forms endowed with semi-symmetric non-metric connections. Symmetry 8(11), 113 (2016)
Hong, Y., Houh, C.H.: Lagrangian submanifolds of quaternion Kaehlerian manifolds satisfying Chen’s equality. Beitr. Algebra Geom. 39(2), 413–421 (1998)
Lee, C.W., Lee, J.W., Vîlcu, G.-E.: Optimal inequalities for the normalized \(\delta \)-Casorati curvatures of submanifolds in Kenmotsu space forms. Adv. Geom. 17(3), 355–362 (2017)
Lee, J.W., Lee, C.W., Vîlcu, G.-E.: Classification of Casorati ideal Legendrian submanifolds in Sasakian space forms. J. Geom. Phys. 155, 103768 (2020)
Lee, J.W., Lee, C.W., Vîlcu, G.-E.: Classification of Casorati ideal Legendrian submanifolds in Sasakian space forms II. J. Geom. Phys. 171, 104410 (2021)
Lee, J.W., Vîlcu, G.-E.: Inequalities for generalized normalized \(\delta \)-Casorati curvatures of slant submanifolds in quaternionic space forms. Taiwan. J. Math. 19(3), 691–702 (2015)
Lone, M.A.: Basic inequalities for submanifolds of quaternionic space forms with a quarter-symmetric connection. J. Geom. Phys. 159, 103927 (2021)
Lone, M.A., Shahid, M.H., Vîlcu, G.-E.: On Casorati curvatures of submanifolds in pointwise Kenmotsu space forms. Math. Phys. Anal. Geom. 22(1), 2 (2019)
Lone, M.S., Lone, M.A., Mihai, A.: A characterization of totally real statistical submanifolds in quaternion Kaehler-like statistical manifolds. Rev. R. Acad. Cienc. Exactas Fis. Nat. Ser. A Mat. RACSAM 116, 55 (2022)
Marchiafava, S.: Submanifolds of (para)-quaternionic Kähler manifolds. Note Mat. 28(suppl. 1), 295–316 (2008)
Marchiafava, S., Piccinni, P., Pontecorvo, M. (Eds.).: Quaternionic structures in mathematics and physics. In: Proceedings of the 2nd Meeting. Rome, September 6–10, 1999, World Scientific Publishing Co., Inc., River Edge, NJ (2001)
Oh, Y.M., Kang, J.H.: The explicit representation of flat Lagrangian H-umbilical submanifolds in quaternion Euclidean spaces. Math. J. Toyama Univ. 27, 101–110 (2004)
Oh, Y.M., Kang, J.H.: Lagrangian \( H \)-umbilical submanifolds in quaternion Euclidean spaces. Tsukuba J. Math. 29(1), 233–245 (2005)
Oprea, T.: Chen’s inequality in the Lagrangian case. Colloq. Math. 108, 163–169 (2007)
Ortega, M., de Dios Pérez, J.: D-Einstein real hypersurfaces of quaternionic space forms. Ann. Mat. Pura Appl. 178, 33–44 (2000)
Park, K.-S.: Inequalities for the Casorati curvatures of real hypersurfaces in some Grassmannians. Taiwan. J. Math. 22(1), 63–77 (2018)
Salamon, S.: Quaternionic Kähler manifolds. Invent. Math. 67(1), 143–171 (1982)
Shu, S., et al.: Totally real submanifolds in a quaternion projective space. Tokyo J. Math. 19(2), 411–418 (1996)
Slesar, V., Şahin, B., Vîlcu, G.-E.: Inequalities for the Casorati curvatures of slant submanifolds in quaternionic space forms. J. Inequal. Appl. 2014(1), 1–10 (2014)
Suh, Y.J., Tripathi, M.M.: Inequalities for algebraic Casorati curvatures and their applications II. In Hermitian–Grassmannian Submanifolds, 85–200, Springer (2017)
Tripathi, M.M.: Inequalities for algebraic Casorati curvatures and their applications. Note Mat. 37(supp1), 161–186 (2017)
Uddin, S.: Geometry of warped product semi-slant submanifolds of Kenmotsu manifolds. Bull. Math. Sci. 8(3), 435–451 (2018)
van Doorn, A., Koenderink, J.J., Pont, S.: Shading, a View from the Inside. Seeing Perceiv. 25(3–4), 303–338 (2012)
Vîlcu, G.-E.: An optimal inequality for Lagrangian submanifolds in complex space forms involving Casorati curvature. J. Math. Anal. Appl. 465(2), 1209–1222 (2018)
Zhang, P., Zhang, L.: Inequalities for Casorati curvatures of submanifolds in real space forms. Adv. Geom. 16(3), 329–335 (2016)
Acknowledgements
G.-E. Vîlcu was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS/CCCDI - UEFISCDI, project number PN-III-P4-ID-PCE-2020-0025, within PNCDI III.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Aquib, M., Lone, M.S., Neacşu, C. et al. On \(\delta \)-Casorati curvature invariants of Lagrangian submanifolds in quaternionic Kähler manifolds of constant q-sectional curvature. Rev. Real Acad. Cienc. Exactas Fis. Nat. Ser. A-Mat. 117, 107 (2023). https://doi.org/10.1007/s13398-023-01438-2
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s13398-023-01438-2
Keywords
- Casorati curvature
- Mean curvature
- \(\delta \)-invariant
- quaternionic Kähler manifold
- Quaternionic space form
- Lagrangian submanifold
- Totally geodesic submanifold
- H-umbilical submanifold