English

An example of anti-dynamo conformal Arnold metric

Fluid Dynamics 2007-05-23 v1 Astrophysics General Relativity and Quantum Cosmology Differential Geometry

Abstract

A 3D metric conformally related to Arnold cat fast dynamo metric: dsA2=eλzdp2+eλzdq2+dz2{ds_{A}}^{2}=e^{-{\lambda}z}dp^{2}+e^{{\lambda}z}dq^{2}+dz^{2} is shown to present a behaviour of non-dynamos where the magnetic field exponentially decay in time. The Riemann-Christoffel connection and Riemann curvature tensor for the Arnold and its conformal counterpart are computed. The curvature decay as z-coordinates increases without bounds. Some of the Riemann curvature components such as RpzpzR_{pzpz} also undergoes dissipation while component RqzqzR_{qzqz} increases without bounds. The remaining curvature component RpqpqR_{pqpq} is constant on the torus surface. The Riemann curvature invariant K2=RijklRijklK^{2}=R_{ijkl}R^{ijkl} is found to be 0.155 for the λ=0.75{\lambda}=0.75. A simple solution of Killing equations for Arnold metric yields a stretch Killing vector along one direction and compressed along other direction in order that the modulus of the Killing vector is not constant along the flow. The flow is shown to be untwisted. The stability of the two metrics are found by examining the sign of their curvature tensor components.

Keywords

Cite

@article{arxiv.physics/0703143,
  title  = {An example of anti-dynamo conformal Arnold metric},
  author = {Garcia de Andrade},
  journal= {arXiv preprint arXiv:physics/0703143},
  year   = {2007}
}