论文标题
多粒子指数与空间等离子体中温度各向异性之间的关系
Relationship between polytropic index and temperature anisotropy in space plasmas
论文作者
论文摘要
该论文在多粒素指数和温度各向异性之间建立了理论关系，这可能表征了空间等离子体。该推导基于颗粒的动能与各向异性kappa分布描述的速度之间的相关性。相关系数取决于速度分布函数的有效维度，其形状由由环境磁场引起的温度各向异性决定。另一方面，有效维度直接取决于多粒子指数。该分析导致相关系数，速度空间的有效尺寸与多粒子指数之间的联系，温度各向异性的比率。此外，进行了数据和统计分析，以测试理论开发的模型的应用，在太阳风质质子等离子体附近1 AU中。派生的理论关系与观察结果非常吻合，表明绝热多环反应指数的最低和经典价值发生在各向同性情况下，而较高的指数则表征各向异性等离子体。最后，进一步讨论了考虑（i）非绝热的多蚀行为以及（ii）更多一般分布的理论的可能扩展。
The paper develops a theoretical relationship between the polytropic index and the temperature anisotropy that may characterize space plasmas. The derivation is based on the correlation among the kinetic energies of particles with velocities described by anisotropic kappa distributions. The correlation coefficient depends on the effective dimensionality of the velocity distribution function, having its shape determined by the temperature anisotropies caused by the ambient magnetic field; on the other hand, the effective dimensionality is directly dependent on the polytropic index. This analysis leads to the connection between the correlation coefficient, effective dimensionality of velocity space, and the polytropic index, with the ratio of temperature anisotropy. Moreover, a data and statistical analysis is performed to test the application of the theoretically developed model, in the solar wind proton plasma near 1 AU. The derived theoretical relationship is in good agreement with observations, showing that the lowest and classical value of the adiabatic polytropic index occurs in the isotropic case, while higher indices characterize anisotropic plasmas. Finally, possible extensions of the theory considering (i) non-adiabatic polytropic behavior, and (ii) more general distributions, are further discussed.
