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On Dirac equations for linear magnetoacoustic waves propagating in an isothermal atmosphereA new analytical approach to study linear magnetoacoustic waves propagating in an isothermal, stratified, and uniformly magnetized atmosphere is presented. The approach is based on Dirac equations, and the theory of Sturm-Liouville operators is used to investigate spectral properties of the obtained Dirac Hamiltonians. Two cases are considered: (1) the background magnetic field is vertical, and the waves are separated into purely magnetic (transverse) and purely acoustic (longitudinal) modes; and (2) the field is tilted with respect to the vertical direction and the magnetic and acoustic modes become coupled giving magnetoacoustic waves. For the first case, the Dirac Hamiltonian possesses either a discrete spectrum, which corresponds to standing magnetic waves, or a continuous spectrum, which can be clearly identified with freely propagating acoustic waves. For the second case, the quantum mechanical perturbation calculus is used to study coupling and energy exchange between the magnetic and acoustic components of magnetoacoustic waves. It is shown that this coupling may efficiently prevent trapping of magnetoacoustic waves instellar atmospheres.
Document ID
19950040618
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Alicki, R.
(Univ. of Gdansk Gdansk, Poland)
Musielak, E. Z.
(Univ. of Gdansk Gdansk, Poland)
Sikorski, J.
(Univ. of Gdansk Gdansk, Poland)
Makowiec, D.
(Univ. of Gdansk Gdansk, Poland)
Date Acquired
August 16, 2013
Publication Date
June 1, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 427
Issue: 2
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A72217
Funding Number(s)
CONTRACT_GRANT: NSF ATM-91-19580
CONTRACT_GRANT: PB-22106-91-02
CONTRACT_GRANT: NAGW-2933
CONTRACT_GRANT: NSF INT-90-165
CONTRACT_GRANT: NSF AST-91-15191
Distribution Limits
Public
Copyright
Other

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