## Tohoku Mathematical Journal

### Jacobi fields along harmonic 2-spheres in 3- and 4-spheres are not all integrable

#### Abstract

In a previous paper, we showed that any Jacobi field along a harmonic map from the 2-sphere to the complex projective plane is integrable (i.e., is tangent to asmooth variation through harmonic maps). In this paper, in contrast, we show that there are (non-full) harmonic maps from the 2-sphere to the 3-sphere and 4-sphere which have non-integrable Jacobi fields. This is particularly surprising in the case of the 3-sphere where the space of harmonic maps of any degree is a smooth manifold, each map having image in a totally geodesic 2-sphere.

#### Article information

Source
Tohoku Math. J. (2), Volume 61, Number 2 (2009), 165-204.

Dates
First available in Project Euclid: 24 June 2009

https://projecteuclid.org/euclid.tmj/1245849442

Digital Object Identifier
doi:10.2748/tmj/1245849442

Mathematical Reviews number (MathSciNet)
MR2541404

Zentralblatt MATH identifier
1184.58006

#### Citation

Lemaire, Luc; Wood, John C. Jacobi fields along harmonic 2-spheres in 3- and 4-spheres are not all integrable. Tohoku Math. J. (2) 61 (2009), no. 2, 165--204. doi:10.2748/tmj/1245849442. https://projecteuclid.org/euclid.tmj/1245849442

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