Suppressed fluctuations..
| dc.creator | de Andrade, L. C. Garcia | |
| dc.date | 2008-06-20 | |
| dc.date.accessioned | 2026-07-07T09:46:01Z | |
| dc.date.available | 2026-07-07T09:46:01Z | |
| dc.description | Suppression of fluctuations of normally perturbed magnetic fields in dynamo waves and slow dynamos along curved (folded), torsioned (twisted) and non-stretched, diffusive filaments are obtained. This form of fluctuations suppression has been recently obtained by Vainshtein et al [PRE 56, (1997)] in nonlinear ABC and stretch-twist-fold (STF) dynamos by using a magnetic Reynolds number of the order of $Rm\approx{10^{4}}$. Here when torsion does not vanish an expression between magnetic Reynolds number and length scale L as with constant torsion $τ_{0}$ itself is obtained, such as $Rm\approx{\frac{τ_{0}L}η}$ is obtained. At coronal loops $Rm\approx{10^{12}}$ and torsion of the twisted structured loop from astronomical data by Lopez-Fuentes et al [Astron. and Astrophys. (2003)] of $τ\approx{9.0{\times}10^{-10}}cm^{-1}$ is used to compute a very slow magnetic diffusion of $η\approx{10^{-8}}$. The slow dynamo obtained here is in agreement with Vishik arguement that fast dynamo cannot be obtained in non-stretched dynamo flows. When torsion vanishes helical turbulence is quenched and but $α$-dynamos cannot be maintained since exponential stretching depends on torsion. This is actually Zeldovich antidynamo theorem for torsion-free or planar filaments which has been discussed by the other also recently in another context [Astr Nach. (2008)]. The suppression of magnetic field fluctuations is actually a result of the coupling of the magnetic diffusion and Frenet torsion of helical turbulence. | |
| dc.identifier | https://arxiv.org/abs/0806.3476 | |
| dc.identifier | http://arxiv.org/abs/0806.3476 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/163389 | |
| dc.subject | Astrophysics | |
| dc.title | Suppressed fluctuations.. | |
| dc.type | text |