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Harmonic morphisms from solvable Lie groups

Published online by Cambridge University Press:  01 September 2009

SIGMUNDUR GUDMUNDSSON
Affiliation:
Department of Mathematics, Faculty of Science, Lund University, Box 118, S-22100 Lund, Sweden. e-mail: [email protected]
MARTIN SVENSSON
Affiliation:
Department of Mathematics & Computer Science, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark. e-mail: [email protected]

Abstract

In this paper we introduce two new methods for constructing harmonic morphisms from solvable Lie groups. The first method yields global solutions from any simply connected nilpotent Lie group and from any Riemannian symmetric space of non-compact type and rank r ≥ 3. The second method provides us with global solutions from any Damek–Ricci space and many non-compact Riemannian symmetric spaces. We then give a continuous family of 3-dimensional solvable Lie groups not admitting any complex-valued harmonic morphisms, not even locally.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 2009

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References

REFERENCES

[1]Baird, P. and Eells, J.A conservation law for harmonic maps, Geometry Symposium Utrecht 1980. Springer Lecture Notes in Mathematics 894 (1981), 125.Google Scholar
[2]Baird, P. and Wood, J. C.Harmonic morphisms, Seifert fibre spaces and conformal foliations. Proc. London Math. Soc. 64 (1992), 170197.CrossRefGoogle Scholar
[3]Baird, P. and Wood, J. C.Harmonic Morphisms Between Riemannian Manifolds (Oxford University Press, 2003).Google Scholar
[4]Berndt, J., Tricerri, F. and Vanhecke, L.Generalized Heisenberg groups and Damek-Ricci harmonic spaces. Springer Lecture Notes in Mathematics 1598 (1995).Google Scholar
[5]Damek, E. and Ricci, F.A class of nonsymmetric harmonic Riemannian spaces. Bull. Amer. Math. Soc. (N.S.) 27 (1992), 139142.CrossRefGoogle Scholar
[6]Fuglede, B.Harmonic morphisms between Riemannian manifolds. Ann. Inst. Fourier 28 (1978), 107144.CrossRefGoogle Scholar
[8]Gudmundsson, S. and Svensson, M.Harmonic morphisms from the Grassmannians and their non-compact duals. Ann. Global Anal. Geom. 30 (2006), 313333.CrossRefGoogle Scholar
[9]Gudmundsson, S. and Svensson, M.Harmonic morphisms from the compact semisimple Lie groups and their non-compact duals. Differential Geom. Appl. 24 (2006), 351366.Google Scholar
[10]Gudmundsson, S. and Svensson, M.On the existence of harmonic morphisms from certain symmetric spaces. J. Geom. Phys. 57 (2007), 353366.CrossRefGoogle Scholar
[11]Helgason, S.Differential Geometry, Lie Groups and Symmetric Spaces (Academic Press, 1978).Google Scholar
[12]Ishihara, T.A mapping of Riemannian manifolds which preserves harmonic functions. J. Math. Kyoto Univ. 19 (1979), 215229.Google Scholar
[13]Malcev, A. I.On a class of homogeneous spaces. Amer. Math. Soc. Trans. Ser. (1) 9 (1962), 267307.Google Scholar
[14]Milnor, J.Curvatures of left invariant metrics on Lie groups. Adv. Math. 21 (1976), 293329.Google Scholar
[15]Nomizu, K.On the cohomology of compact homogeneous spaces of nilpotent Lie groups. Ann. Math. 59 (1954), 531538.CrossRefGoogle Scholar