Home Weakly Einstein Equivalence in a Golden Space Form and Certain CR-submanifolds
Article
Licensed
Unlicensed Requires Authentication

Weakly Einstein Equivalence in a Golden Space Form and Certain CR-submanifolds

  • Jihun Kim , Jeonghyeong Park and Bayram Şahin
Published/Copyright: December 18, 2023
Become an author with De Gruyter Brill

ABSTRACT

It is known that the Golden space form may not be an Einstein manifold. In this paper, it is shown that the condition to be Einstein for a Golden space form is equivalent to being weakly Einstein. In addition, the partial geodesic and cyclic parallelism of the CR-submanifolds of a Golden space are examined, and the case of the constant Golden sectional curvature is determined. Moreover, the CR-submanifolds with semi-flat normal connection are studied and an inequality is obtained. The equality case of this inequality is also checked. We also consider the totally umbilical CR-submanifold of Golden Riemannian manifolds and show that such submanifolds are totally geodesic under certain conditions. Furthermore, we obtain an inequality involving the scalar curvature of CR-submanifold and check the existence of extrinsic spheres in Golden space forms.

2020 Mathematics Subject Classification: Primary 53C15; 53C25; Secondary 53C40

(Communicated by Tibor Macko)


This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2019R1A2C1083957).

REFERENCES

[1] Ahmad, M.—Qayyoom, M. A.: On Submanifolds in a Riemannian manifold with golden structure, Turk. J. Math. Comput. Sci. 11 (2019), 8–23.Search in Google Scholar

[2] CRăsmăreanu, M.—Hreţcanu, C. E.: Golden differential geometry, Chaos Solitons Fractals 38 (2008), 1229–1238.10.1016/j.chaos.2008.04.007Search in Google Scholar

[3] Erdoğan, F. E.—Yildirim, C.: On a study of the totally umbilical semi-invariant submanifolds of Golden Riemannian manifolds, J. Polytechnic 21 (2018), 967–970.10.2339/politeknik.389629Search in Google Scholar

[4] Erdoğan, F. E.—Yildirim, C.: Semi-invariant submanifolds of Golden Riemannian manifolds, AIP Conference Proceedings 1833 (2017), Art. ID 020044.10.1063/1.4981692Search in Google Scholar

[5] Euh, Y.—Park, J. H.—Sekigawa, K.: A curvature identity on a 4-dimensional Riemannian manifold, Results Math. 63 (2013), 107–114.10.1007/s00025-011-0164-3Search in Google Scholar

[6] Euh, Y.—Park, J. H.—Sekigawa, K.: A generalization of a 4-dimensional Einstein manifold, Math. Slovaca 63 (2013), 595–610.10.2478/s12175-013-0121-6Search in Google Scholar

[7] Gezer, A.—Cengiz, N.—Salimov, A.: On integrability of golden Riemannian structures, Turkish J. Math. 37 (2013), 693–703.10.3906/mat-1108-35Search in Google Scholar

[8] Gherici, B.: Induced structures on golden Riemannian manifolds, Beitr. Algebra. Geom. 59 (2018), 761–777.10.1007/s13366-018-0392-8Search in Google Scholar

[9] Gök, M.—Keleş, S.—Kiliç, E.: Some characterizations of semi-invariant submanifolds of golden Riemannian manifolds, Mathematics 7 (2019), Article ID 1209.10.3390/math7121209Search in Google Scholar

[10] Gök, M.—Keleş, S.—Kiliç, E.: Schouten and Vrănceanu connections on golden manifolds, Int. Electron. J. Geom. 12 (2019), 169–181.10.36890/iejg.628070Search in Google Scholar

[11] Gök, M.—Kiliç, E.: Invariant submanifolds in golden Riemannian manifolds, Commun. Fac. Sci. Univ. Ank. Ser. A1 Math. Stat. 69 (2020), 125–138.10.31801/cfsuasmas.635434Search in Google Scholar

[12] Gök, M.—Kiliç, E.: Non-invariant submanifolds of locally decomposable golden Riemannian manifolds, Arab. J. Math. 10 (2021), 77–89.10.1007/s40065-020-00307-9Search in Google Scholar

[13] HREţcanu, C. E.—Crăsmăreanu, M.: On some invariant submanifolds in a Riemannian manifold with golden structure, An. ştiinţ. Univ. Al. I. Cuza Iaşi. Mat. (N.S.) 53 (2007), 199–211.Search in Google Scholar

[14] Hreţcanu, C. E.—Crăsmăreanu, M.: Applications of the golden ratio on Riemannian manifolds, Turkish J. Math. 33 (2009), 179–191.10.3906/mat-0711-29Search in Google Scholar

[15] Özkan, M.: Prolongations of golden structures to tangent bundles, Differ. Geom. Dyn. Syst. 16 (2014), 227–238.Search in Google Scholar

[16] Şahin, B.—Akyol, M. A.: Golden maps between golden Riemannian manifolds and constancy of certain maps, Math. Commun. 19 (2014), 333–342.Search in Google Scholar

[17] Şahin, F.—Şahin, B.—Erdoğan, F. E.: Golden Riemannian manifolds having constant sectional curvatures and their submanifolds, Mediterr. J. Math. 19 (2022), Art. No. 171.10.1007/s00009-022-02094-3Search in Google Scholar

[18] Yano, K.—Kon, M.: Structures on Manifolds, World Scientific Publishing Co., Singapore, 1984.10.1142/0067Search in Google Scholar

Received: 2022-09-05
Accepted: 2023-02-17
Published Online: 2023-12-18

© 2023 Mathematical Institute Slovak Academy of Sciences

Downloaded on 25.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/ms-2023-0117/html
Scroll to top button