2008年12月2日
Propagation of electromagnetic waves in resistive pair plasma and causal relativistic magnetohydrodynamics
Physical Review D - Particles, Fields, Gravitation and Cosmology
- 巻
- 78
- 号
- 12
- 記述言語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1103/PhysRevD.78.125026
We investigate the propagation of electromagnetic waves in resistive e± pair plasmas using a one-fluid theory derived from the relativistic two-fluid equations. When the resistivity normalized by the electron/positron inertia variable exceeds a critical value, the dispersion relation for electromagnetic waves shows that the group velocity is larger than the light speed in vacuum. However, in such a case, it also is found that the plasma parameter is less than unity: that is, the electron-positron pair medium no longer can be treated as plasma. Thus, the simple two-fluid approximation is invalid. This confirms that superluminal propagation of electromagnetic wave is forbidden in a plasma-a conclusion consistent with the relativistic principle of causality. As an alternative, we propose a new set of equations for "causal relativistic magnetohydrodynamics," which both have nonzero resistivity and yet are consistent with the causality principle. © 2008 The American Physical Society.
- リンク情報
- ID情報
-
- DOI : 10.1103/PhysRevD.78.125026
- ISSN : 1550-7998
- eISSN : 1550-2368
- SCOPUS ID : 58149471094