Magnetohydrodynamic flows as Newtonian-type gravitational motions

• Authors: Nikolaos Spyrou , Christos Tsagas
• Languages of publication: EN

Abstracts

EN

We study the motion of a magnetised, highly conductive fluid within the framework of Newtonian gravity. Our analysis examines whether and under what conditions magnetohydrodynamic flows can be represented as hydrodynamic ones and then as Newtonian-type gravitational motions. In the latter case we define a generalised effective density and an effective Poisson-type potential, which include the magnetic input and determine the dynamics of the magnetised system. Introducing the dynamical equivalence of the aforementioned two representations, we use it to test mass measurements based on purely gravitational motions. We also provide the generalised Raychaudhuri equation corresponding to the aforementioned effective potential and discuss its implications for the kinematics of the fluid.

Keywords

EN

mathematical physics; magnetohydrodynamics

• Journal: Open Physics
• Year: 2010
• Volume: 8
• Issue: 6
• Pages: 989-994

Dates

published

1 - 12 - 2010

online

5 - 9 - 2010

Contributors

author

Nikolaos Spyrou

• Department of Astronomy, Aristoteleion University of Thessaloniki, 541.24, Thessaloniki, Greece,

author

Christos Tsagas

• Department of Astronomy, Aristoteleion University of Thessaloniki, 541.24, Thessaloniki, Greece

References

• [1] U. Klein, R. Wielebinski, H. W. Morsi, Astron. Astrophys. 190, 41 (1988)
• [2] P. P. Kronberg, Rep. Prog. Phys. 57, 325 (1994) http://dx.doi.org/10.1088/0034-4885/57/4/001[Crossref]
• [3] J.-L. Han, R. Wielebinski, Chinese J. Astron. Ast. 2, 293 (2002) http://dx.doi.org/10.1088/1009-9271/2/4/293[Crossref]
• [4] N. I. Shakura, R. A. Sunyaev, Astron. Astrophys. 24, 337 (1973)
• [5] S. A. Balbus, J. F. Hawley, Astrophys. J. 376, 214 (1991) http://dx.doi.org/10.1086/170270[Crossref]
• [6] D. Biskamp, Magnetohydrodynamic Turbulense (Cambridge University Press, Cambridge, 2003) http://dx.doi.org/10.1017/CBO9780511535222[Crossref]
• [7] T. V. Ruzmaikina, A. A. Ruzmaikin, Sov. Astron. 14, 963 (1971)
• [8] D. Papadopoulos, P. Esposito, Astrophys. J. 257, 10 (1982) http://dx.doi.org/10.1086/159956[Crossref]
• [9] K. Subramanian, J. D. Barrow, Phys. Rev. D 58, 083502 (1998) http://dx.doi.org/10.1103/PhysRevD.58.083502[Crossref]
• [10] M. Giovannini, Int. J. Mod. Phys. D 13, 391 (2004) http://dx.doi.org/10.1142/S0218271804004530[Crossref]
• [11] K. Kleidis, N. K. Spyrou, Classical Quant. Grav. 17, 2965 (2000) http://dx.doi.org/10.1088/0264-9381/17/15/308[Crossref]
• [12] N. K. Spyrou, C. G. Tsagas, Classical Quant. Grav. 21, 2435 (2004) http://dx.doi.org/10.1088/0264-9381/21/9/017[Crossref]
• [13] E. N. Parker, Cosmical Magnetic Fields (Oxford University Press, Oxford, 1979)
• [14] Y. B. Zeldovich, A. A. Ruzmaikin, D. D. Sokoloff, Magnetic Fields in Astrophysics (McGraw-Hill, New York, 1983)
• [15] L. Mestel, Stellar Magnetism (Oxford University Press, Oxford, 1999)
• [16] S. Chandrasekhar, Astrophys. J 158, 45 (1969) http://dx.doi.org/10.1086/150170[Crossref]
• [17] N. K. Spyrou, In: P. G. Laskarides (Ed.), Proceedings of the 6th Hellenic Astronomical Conference (2004) 229, http://www.astro.auth.gr/elaset/helasmtg/2003/
• [18] N. K. Spyrou, In: N. K. Spyrou, N. Stergioulas, C. Tsagas (Eds.), Cosmology and Gravitational Physics (2006) 57, http://www.astro.auth.gr/Cosmology05/
• [19] N. K. Spyrou, In: M. Plionis, S. Cotsakis (Eds.), Modern Theoretical and Observational Cosmology (Kluwer Academic Publishers, Netherlands, 2002) 35

Identifiers

DOI

10.2478/s11534-010-0004-1