Abstract
We study harmonic vector fields on a Lorentzian torus T 2 i.e. critical points of the total bending functional \({\mathcal {B} : \mathcal {E} \to \mathbb {R}}\) were \({\mathcal {E}}\) consists of all unit timelike vector fields on T 2. We derive the first variation formula for \({\mathcal {B}}\) in terms of the Lorentz angle function associated to each \({X \in \mathcal {E}}\) and give applications on flat Lorentzian tori.
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Burns J.T.: Curvature functions on Lorentz 2-manifolds. Pac. J. Math. 70(2), 325–335 (1977)
Dragomir S., Perrone D.: On the geometry of tangent hyperquadric bundles: CR and pseudoharmonic vector fields. Ann. Glob. Ann. Geom. 30, 211–238 (2006)
Gil-Medrano O., Hurtado A.: Spacelike energy of timelike unit vector fields on a Lorentzian manifold. J.Geom. Phys. 51, 82–100 (2004)
Han S.D., Yim J.W.: Unit vector fields on spheres which are harmonic maps. Math. Z. 227, 83–92 (1998)
Hurtado A.: Instability of Hopf vector fields on Lorentzian Berger spheres. Isr. J. Math. 177, 103–124 (2010)
Ishihara T.: Harmonic sections of tangent bundles. J. Math. Tokushima Univ. 13, 23–27 (1979)
Kazdan J., Warner F.: Curvature functions for compact 2-manifolds. Ann. Math. 99, 14–47 (1974)
O’Neill B.: Semi-Riemannian geometry. Academic Press, New York-London-Paris (1983)
Weinstein T.: An introduction to Lorentz surfaces. vol. 22. De Gruyter Expositions in Mathematics, Berlin-New York (1996)
Wiegmink G.: Total bending of vector fields on Riemannian manifolds. Math. Ann. 303(2), 325–344 (1995)
Wood C.M.: On the energy of a unit vector field. Geom. Dedic. 64, 319–330 (1997)
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Dragomir, S., Soret, M. Harmonic vector fields on compact Lorentz surfaces. Ricerche mat. 61, 31–45 (2012). https://doi.org/10.1007/s11587-011-0113-1
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DOI: https://doi.org/10.1007/s11587-011-0113-1