标题： 日冕环的黎曼扭曲流体流的不稳定性 显示英文标题

标题： Geodesic plasma flows instabilities of Riemann twisted solar loops

摘要： 在黎曼流形中计算磁化扭缠通量管的黎曼曲率和截面曲率，以研究等离子体天体物理管的稳定性。 使用测地线方程表明，在厚磁管的情况下，平面（无弗雷内扭转）管的曲率会对沿管流动的速度产生阻尼效应。 通过使用负截面曲率法研究黎曼扭曲薄管（接近细丝）中测地线流相对于恒定径向扰动的稳定性。 未承认任何特殊形式的流动（如Beltrami流动），并且对于薄磁通量管的情况，证明具有普遍性。 在磁平衡状态下，管的扭结也被证明会对等离子体流动的环向速度产生阻尼效应。 发现对于正扰动和流速的角速度，由于磁化扭缠管度规的截面Ricci曲率为负，因此会发生不稳定性。 太阳耀斑的产生可能源于这些扭曲的日冕环的几何不稳定性。 显示英文摘要

摘要： Riemann and sectional curvatures of magnetic twisted flux tubes in Riemannian manifold are computed to investigate the stability of the plasma astrophysical tubes. The geodesic equations are used to show that in the case of thick magnetic tubes, the curvature of planar (Frenet torsion-free) tubes have the effect ct of damping the flow speed along the tube. Stability of geodesic flows in the Riemannian twisted thin tubes (almost filaments), against constant radial perturbations is investigated by using the method of negative sectional curvature for unstable flows. No special form of the flow like Beltrami flows is admitted, and the proof is general for the case of thin magnetic flux tubes. In the magnetic equilibrium state, the twist of the tube is shown to display also a damping effect on the toroidal velocity of the plasma flow. It is found that for positive perturbations and angular speed of the flow, instability is achieved, since the sectional Ricci curvature of the magnetic twisted tube metric is negative. Solar flare production may appear from these geometrical instabilities of the twisted solar loops.