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Harmonic maps from surfaces into pseudo-Riemannian spheres and hyperbolic spaces

Published online by Cambridge University Press:  24 October 2008

S. Erdem
Affiliation:
University of Leeds

Extract

In [2, 4, 5, 6, 7] Calabi, Barbosa and Chern showedthat there is a 2:1 correspondence between arbitrary pairs of full isotropic (terminology as in [8]) harmonic maps ±φ:M→S2m from a Riemann surface to a Euclidean sphere and full totally isotropic holomorphic maps f:M→2m from the surface to complex projective space. In this paper we show, very explicitly, how to construct a similar one-to-one correspondence when S2m is replaced by some other space forms of positive and negative curvatures with their standard (indefinite) metrics obtained by restricting a standard (indefinite) bilinear form on Euclidean space to the tangent spaces. We get over a difficulty encountered by Barbosa of dealing with the zeros of a certain wedge product by a technique adapted from [8]. The case of complex projective space forms (indefinite complex projective and complex hyperbolic spaces) will be considered in a separate paper. Some further developments in classification theorems are given by Eells and Wood [8], Rawnsley[14], [15] and Erdem and Wood [10].

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1983

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References

REFERENCES

[1] Baird, P.. Harmonic maps with symmetry, harmonic morphisms and deformations of metrics. Ph.D. thesis, Warwick University, 1981.Google Scholar
[2] Barbosa, J.. On minimal immersions of S 2 into S 2m. Trans. Amer. Math. Soc. 210 (1975), 75106.Google Scholar
[3] Borchers, H. J. and Garber, W. D.. Local theory of solutions for the 0(2k+1)-model. Comm. Math. Phys. 72 (1980), 77102.CrossRefGoogle Scholar
[4] Calabi, E.. Minimal immersions of surfaces in Euclidean spheres. J. Differential Geom. 1 (1967), 111125.CrossRefGoogle Scholar
[5] Calabi, E.. Quelques applications de l'analyse complexe aux surfaces d'aire minima. In Topics in Complex Manifolds (University of Montreal, 1967), 5981.Google Scholar
[6] Chern, S. S.. On the minimal immersions of the two-sphere in a space of constant curvature. Problems in Analysis (Princeton University Press, 1970), 2740.Google Scholar
[7] Chern, S. S.. On minimal spheres in the four sphere. In Studies and Essays Presented to Y. W. Chen (Taiwan, 1970), 137150.Google Scholar
[8] Eells, J. and Wood, J. C.. Harmonic maps from surfaces to complex projective spaces. Adv. in Math. (In the Press.)Google Scholar
[9] Eells, J. and Sampson, J. H.. Harmonic mappings of Riemannian manifolds. Amer. J. Math. 86 (1964), 109159.CrossRefGoogle Scholar
[10] Erdem, S. and Wood, J. C.. On the construction of harmonic maps into a Grassmannian. J. London Math. Soc. (1983). (In the Press.)CrossRefGoogle Scholar
[11] Kobayashi, S. and Nomizu, K.. Foundations of Differential Geometry, vol. I, II (Wiley Interscienee, 1963, 1969).Google Scholar
[12] Koszul, J. L. and Malorange, B.. Sur certaines structure fibrés complexes. Arch. Math. 9 (1958), 102109.CrossRefGoogle Scholar
[13] Petrowski, I.. Sur l'analyticité des solutions des systèmes d'équations différentielles. Mat. Sb. (N.S.) 5 (47), (1939), 370.Google Scholar
[14] Rawnsley, J. H.. On the rank of horizontal maps. Math. Proc. Cambridge Philos. Soc. 92 (1982), 485488.CrossRefGoogle Scholar
[15] Rawnsley, J. H.. Notes on Homogeneous Spaces. (Preprint, University of Warwick, 1982.)Google Scholar
[16] Wolf, J. A.. Spaces of Constant Curvature (McGraw-Hill, 1967).Google Scholar
[17] Wood, J. C.. Harmonic Maps and Complex Analysis, Proc. Summer Course in Com plex Analysis, vol. III (Trieste, 1976), pp. 289308.Google Scholar
[18] Wu, H.. The Equidistribution Theory of Holomorphic Curves. Annals of Mathematics Studies, no. 64 (Princeton University Press, 1970).CrossRefGoogle Scholar