Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-17T18:06:00.782Z Has data issue: false hasContentIssue false

PINCHING THEOREMS FOR A COMPACT MINIMAL SUBMANIFOLD IN A COMPLEX PROJECTIVE SPACE

Published online by Cambridge University Press:  01 February 2008

MAYUKO KON*
Affiliation:
Department of Mathematics, Hokkaido University, Kita 10 Nishi 8, Sapporo 060-0810, Japan (email: mayuko_k13@math.sci.hokudai.ac.jp)
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We give a formula for the Laplacian of the second fundamental form of an n-dimensional compact minimal submanifold M in a complex projective space CPm. As an application of this formula, we prove that M is a geodesic minimal hypersphere in CPm if the sectional curvature satisfies K≥1/n, if the normal connection is flat, and if M satisfies an additional condition which is automatically satisfied when M is a CR submanifold. We also prove that M is the complex projective space CPn/2 if K≥3/n, and if the normal connection of M is semi-flat.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 2008

References

[1]Bejancu, A., Geometry of CR-submanifolds (D. Reidel, Dordrecht, 1986).CrossRefGoogle Scholar
[2]Chen, B. Y., ‘CR-submanifolds of a Kaehler manifold, II’, J. Differential Geom. 16 (1981), 493509.Google Scholar
[3]Ishihara, I., ‘Kaehler submanifolds satisfying a certain condition on normal connection’, Atti Accad. Naz. Lincei LXII (1977), 3035.Google Scholar
[4]Kon, M., ‘Real minimal hypersurfaces in a complex projective space’, Proc. Amer. Math. Soc. 79 (1980), 285288.CrossRefGoogle Scholar
[5]Lawson, H. B. Jr, ‘Rigidity theorems in rank-1 symmetric spaces’, J. Differential Geom. 4 (1970), 349357.CrossRefGoogle Scholar
[6]Ogiue, K., ‘Differential geometry of Kaehler submanifolds’, Adv. Math. 18 (1974), 73114.CrossRefGoogle Scholar
[7]Okumura, M., ‘Normal curvature and real submanifold of the complex projective space’, Geom. Dedicata 7 (1978), 509517.CrossRefGoogle Scholar
[8]Okumura, M., ‘Submanifolds with L-flat normal connection of the complex projective space’, Pacific J. Math. 78(2) (1978), 447454.CrossRefGoogle Scholar
[9]Simons, J., ‘Minimal varieties in riemannian manifolds’, Ann. of Math. 88 (1968), 62105.CrossRefGoogle Scholar
[10]Takagi, R., ‘Real hypersurfaces in a complex projective space with constant principal curvatures’, J. Math. Soc. Japan 27 (1975), 4353.Google Scholar
[11]Yano, K., ‘On harmonic and Killing vector fields’, Ann. of Math. 55 (1952), 3845.CrossRefGoogle Scholar
[12]Yano, K. and Kon, M., Structures on manifolds (World Scientific, Singapore, 1984).Google Scholar