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Harmonic surfaces in the Cayley plane. (English) Zbl 1470.30037

Summary: We consider the twistor theory of nilconformal harmonic maps from a Riemann surface into the Cayley plane \(\mathbb{O} P^2 = F_4 / \mathrm{Spin} ( 9 )\). By exhibiting this symmetric space as a submanifold of the Grassmannian of 10-dimensional subspaces of the fundamental representation of \(F_4\), techniques and constructions similar to those used in earlier works on twistor constructions of nilconformal harmonic maps into classical Grassmannians can also be applied in this case. The originality of our approach lies on the use of the classification of nilpotent orbits in Lie algebras as described by Djoković.

MSC:

30F99 Riemann surfaces
58E20 Harmonic maps, etc.
53C43 Differential geometric aspects of harmonic maps
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