DOI QR코드

DOI QR Code

CONTACT THREE CR-SUBMANIFOLDS OF A (4m + 3)-DIMENSIONAL UNIT SPHERE

  • Kim, Hyang-Sook (Department of Computational Mathematics School of Computer Aided Science and Institute of Mathematical Sciences Inje University) ;
  • Kim, Young-Mi (Department of Mathematics Silla University) ;
  • Kwon, Jung-Hwan (Department of Mathematics Education Daegu University) ;
  • Pak, Jin-Suk (Department of Mathematics Education Kyungpook National University)
  • Published : 2007.03.31

Abstract

We study an (n+3)($n\;{\geq}\;7-dimensional$ real submanifold of a (4m+3)-unit sphere $S^{4m+3}$ with Sasakian 3-structure induced from the canonical quaternionic $K\"{a}hler$ structure of quaternionic (m+1)-number space $Q^{m+1}$, and especially determine contact three CR-submanifolds with (p-1) contact three CR-dimension under the equality conditions given in (4.1), where p = 4m - n denotes the codimension of the submanifold. Also we provide necessary conditions concerning sectional curvature in order that a compact contact three CR-submanifold of (p-1) contact three CR-dimension in $S^{4m+3}$ is the model space $S^{4n_1+3}(r_1){\times}S^{4n_2+3}(r_2)$ for some portion $(n_1,\;n_2)$ of (n-3)/4 and some $r_1,\;r_2$ with $r^{2}_{1}+r^{2}_{2}=1$.

Keywords

References

  1. A. Bejancu, Geometry of CR-submanifolds, D. Reidel Publishing Company, Dordrecht-Boston-Lancaster-Tokyo, 1986
  2. B. Y. Chen, Geometry of submanifolds, Marcel Dekker Inc., New York, 1973
  3. J. Erbacher, Reduction of the codimension of an isometric immersion, J. Differential Geometry 5 (1971), 333-340
  4. S. Ishihara and M. Konish, Fibred Riemannian spaces with Sasakian 3-structure, Differential Geometry in honor of K. Yano, Kinokuniya, Tokyo, 1972, 179-194
  5. T. Kashiwada, A note on a Riemannian space with Sasakian 3-structure, Nat. Sci. Rep. of the Ochanomizu Univ. 22 (1971), 1-2
  6. Y. Y. Kuo, On almost contact 3-structure, Tohoku Math. J. 22 (1970), 325-332 https://doi.org/10.2748/tmj/1178242759
  7. J.-H. Kwon and J. S. Pak, On contact three CR-submanifolds of a (4m+3)-dimensional unit sphere, Commun. Korean Math. Soc. 13 (1998), no. 3, 561-577
  8. J. S. Pak, Real hypersurfaces in quaternionic Kaehlerian manifolds with constant Qsectional curvature, Kodai Math. Sem. Rep. 29 (1977), no. 1-2, 22-61 https://doi.org/10.2996/kmj/1138833571
  9. P. Ryan, Homogeneity and some curvature condition for hypersurfaces, Tohoku Math. J. 21 (1969), 363-388 https://doi.org/10.2748/tmj/1178242949
  10. S. Tachibana and W. N. Yu, On a Riemannian space admitting more than one Sasakian structures, Tohoku Math. J. 22 (1970), 536-540 https://doi.org/10.2748/tmj/1178242720
  11. K. Yano, Integral formulas in Riemannian geometry, Marcel Dekker Inc., New York, 1970
  12. K. Yano and M. Kon, CR submanifolds of Kaehlerian and Sasakian manifolds, Birkhauser, Boston-Basel-Stuttgart, 1983