In this work, using optimization procedures on Riemannian submanifolds, we obtained two different inequalities on the generalized normalized $ \delta $-Casorati curvatures of warped product submanifolds in complex space forms. We also quantified the conditions under which these inequalities become equalities, providing more insight into their geometric consequences. Further, we described new findings in the form of harmonic functions and Hessian functions, which offer a more general view of the interplay between curvature and analyticity.
Citation: Md Aquib. An optimal inequality for warped product submanifolds in complex space forms[J]. AIMS Mathematics, 2025, 10(8): 18055-18069. doi: 10.3934/math.2025804
In this work, using optimization procedures on Riemannian submanifolds, we obtained two different inequalities on the generalized normalized $ \delta $-Casorati curvatures of warped product submanifolds in complex space forms. We also quantified the conditions under which these inequalities become equalities, providing more insight into their geometric consequences. Further, we described new findings in the form of harmonic functions and Hessian functions, which offer a more general view of the interplay between curvature and analyticity.
| [1] | M. Aquib, M. S. Lone, C. Neacşu, G. E. Vilcu, 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 (2023), 107. https://doi.org/10.1007/s13398-023-01438-2 |
| [2] | M. Aquib, J. W. Lee, G. E. Vilcu, D. W. Yoon, Classification of Casorati ideal Lagrangian submanifolds in complex space forms, Diff. Geom. Appl., 63 (2019), 30–49. https://doi.org/10.1016/j.difgeo.2018.12.006 |
| [3] | M. Aquib, Casorati-type inequalities for submanifolds in s-space forms with semi-symmetric connection, Symmetry, 17 (2015), 1100. https://doi.org/10.3390/sym17071100 |
| [4] |
R. L. Bishop, B. O'Neill, Manifolds of negative curvature, Trans. Amer. Math. Soc., 145 (1969), 1–49. https://doi.org/10.2307/1995057 doi: 10.2307/1995057
|
| [5] |
F. Casorati, Mesure de la courbure des surfaces suivant l'idée commune. Ses rapports avec les mesures de courbure gaussienne et moyenne, Acta Math., 14 (1890), 95–110. https://doi.org/10.1007/BF02413317 doi: 10.1007/BF02413317
|
| [6] |
B. Y. Chen, Some pinching and classification theorems for minimal submanifolds, Arch. Math., 60 (1993), 568–578. https://doi.org/10.1007/BF01236084 doi: 10.1007/BF01236084
|
| [7] | B. Y. Chen, Pseudo-Riemannian geometry, $\delta$-invariants and applications, Hackensack: World Scientific, 2011. https://doi.org/10.1142/8003 |
| [8] | B. Y. Chen, Differential geometry of warped product manifolds and submanifolds, Hackensack: World Scientific, 2017. https://doi.org/10.1142/10419 |
| [9] | S. Decu, S. Haesen, L. Verstraelen, Optimal inequalities involving Casorati curvatures, Bull. Transilv. Univ. Braşov Ser. B, 14 (2007), 85–93. |
| [10] | S. Decu, S. Haesen, L. Verstraelen, Optimal inequalities characterising quasi-umbilical submanifolds, J. Inequal. Pure Appl. Math., 9 (2008), 1–7. |
| [11] |
F. Dillen, J. Fastenakels, On an inequality of Oprea for Lagrangian submanifolds, Cent. Eur. J. Math., 7 (2009), 140–144. https://doi.org/10.2478/s11533-008-0064-2 doi: 10.2478/s11533-008-0064-2
|
| [12] |
S. Haesen, D. Kowalczyk, L. Verstraelen, On the extrinsic principal directions of Riemannian submanifolds, Note Mate., 29 (2009), 41–53. https://doi.org/10.1285/i15900932v29n2p41 doi: 10.1285/i15900932v29n2p41
|
| [13] |
G. Q. He, H. R. Liu, L. Zhang, Optimal inequalities for the Casorati curvatures of submanifolds in generalized space forms endowed with semi-symmetric non-metric connections, Symmetry, 8 (2016), 113–122. https://doi.org/10.3390/sym8110113 doi: 10.3390/sym8110113
|
| [14] |
C. W. Lee, J. W. Lee, G. E. Vîlcu, Optimal inequalities for the normalized $\delta$-Casorati curvatures of submanifolds in Kenmotsu space forms, Adv. Geom., 17 (2017), 355–362. https://doi.org/10.1515/advgeom-2017-0008 doi: 10.1515/advgeom-2017-0008
|
| [15] |
J. W. Lee, G. E. Vîlcu, Inequalities for generalized normalized $\delta$-Casorati curvatures of slant submanifolds in quaternionic space forms, Taiwanese J. Math., 19 (2015), 691–702. https://doi.org/10.11650/tjm.19.2015.4832 doi: 10.11650/tjm.19.2015.4832
|
| [16] |
J. F. Nash, The imbedding problem for Riemannian manifolds, Ann. Math., 63 (1956), 20–63. https://doi.org/10.2307/1969989 doi: 10.2307/1969989
|
| [17] | T. Oprea, Chen's inequality in the Lagrangian case, Colloq. Math., 108 (2007), 163–169. https://eudml.org/doc/283641 |
| [18] | K. S. Park, Inequalities for the Casorati curvatures of real hypersurfaces in some Grassmannians, Taiwanese J. Math., 22 (2018), 63–77. |
| [19] |
P. Zhang, L. Zhang, Remarks on inequalities for the Casorati curvatures of slant submanifolds in quaternionic space forms, J. Inequal. Appl., 2014 (2014), 452. https://doi.org/10.1186/1029-242X-2014-452 doi: 10.1186/1029-242X-2014-452
|
| [20] |
P. Zhang, L. Zhang, Inequalities for Casorati curvatures of submanifolds in real space forms, Adv. Geom., 16 (2016), 329–335. https://doi.org/10.1515/advgeom-2016-0009 doi: 10.1515/advgeom-2016-0009
|