In this paper we study equations of magnetic hydrodynamics with a stress tensor. We interpret this system as the generalized Euler equation associated with an Abelian extension of the Lie algebra of vector fields with a nontrivial 2-cocycle. We use the Lie algebra approach to prove the energy conservation law and the conservation of cross-helicity.

1.
Adams
,
R. A.
,
Sobolev Spaces, Pure and Applied Mathematics
(
Academic
, New York,
1975
), Vol.
65
.
2.
Arnold
,
V.
, “
Sur la géométrie différentielle des groupes de Lie de dimension infinie et ses applications à l’hydrodynamique des fluides parfaits
,”
Ann. Inst. Fourier
16
,
319
361
(
1966
).
3.
Arnold
,
V. I.
and
Khesin
,
B. A.
,
Topological Methods in Hydrodynamics
, Applied Mathematical Sciences, Vol.
125
(
Springer-Verlag
, New York,
1998
).
4.
Batchelor
,
G. K.
,
An Introduction to Fluid Dynamics
(
Cambridge University Press
, Cambridge,
1967
).
5.
Berman
,
S.
and
Billig
,
Y.
, “
Irreducible representations for toroidal Lie algebras
,”
J. Algebra
221
,
188
231
(
1999
).
6.
Billig
,
Y.
, “
Principal vertex operator representations for toroidal Lie algebras
,”
J. Math. Phys.
39
,
3844
3864
(
1998
).
7.
Billig
,
Y.
, “
Energy-momentum tensor for the toroidal Lie algebras
,” math.RT∕0201313.
8.
Billig
,
Y.
, “
Abelian extensions of the group of diffeomorphisms of a torus
,”
Lett. Math. Phys.
64
,
155
169
(
2003
).
9.
Biskamp
,
D.
,
Nonlinear Magnetohydrodynamics
(
Cambridge University Press
, Cambridge,
1993
).
10.
Ebin
,
D.
and
Marsden
,
J.
, “
Groups of diffeomorphisms and the motion of an incompressible fluid
,”
Ann. Math.
92
,
102
163
(
1970
).
11.
Eswara Rao
,
S.
and
Moody
,
R. V.
, “
Vertex representations for N-toroidal Lie algebras and a generalization of the Virasoro algebra
,”
Commun. Math. Phys.
159
,
239
264
(
1994
).
12.
Fuks
,
D. B.
,
Cohomology of Infinite-Dimensional Lie Algebras
(
Consultants Bureau
, New York,
1986
).
13.
Gelfand
,
I. M.
and
Fuks
,
D. B.
, “
Cohomology of Lie algebras of vector fields with nontrivial coefficients
,”
Funkc. Anal. Priloz.
4
,
10
25
(
1970
).
14.
Kadomtsev
,
B. B.
,
Tokamak Plasma: A Complex Physical System
(
Institute of Physics
, Bristol,
1992
).
15.
Larsson
,
T. A.
, “
Lowest-energy representations of non-centrally extended diffeomorphism algebras
,”
Commun. Math. Phys.
201
,
461
470
,
1999
.
16.
Marsden
,
J.
and
Ratiu
,
T.
,
Introduction to Mechanics and Symmetry
, Texts in Appl. Math. (
Springer-Verlag
, New York,
1994
), Vol.
17
.
17.
Marsden
,
J.
,
Ratiu
,
T.
, and
Weinstein
,
A.
, “
Semidirect products and reduction in mechanics
,”
Trans. Am. Math. Soc.
281
,
147
177
(
1984
).
18.
Moffatt
,
H. K.
, “
Vortex- and magneto-dynamics—A topological perspective
,”
Mathematical Physics 2000
(
Imperial College Press
, London,
2000
), pp.
170
182
.
19.
Moffatt
,
H. K.
, “
Some developments in the theory of turbulence
,”
J. Fluid Mech.
106
,
27
47
(
1981
).
20.
Moreau
,
R.
,
Magnetohydrodynamics, Fluid Mechanics and its Applications
(
Kluwer Academic
, Dodrecht,
1990
), Vol.
3
.
21.
Ovsienko
,
V. Yu.
and
Khesin
,
B. A.
, “
The super Korteweg–de Vries equation as an Euler equation
,”
Funkc. Anal. Priloz.
21
,
81
82
(
1987
).
22.
Priest
,
E. R.
,
Solar Magnetohydrodynamics, Geophysics and Astrophysics Monographs
(
D. Reidel
, Dordrecht,
1982
), Vol.
21
.
23.
Rosensweig
,
R. E.
,
Ferrohydrodynamics
(
Cambridge University Press
, Cambridge,
1985
).
24.
Višik
,
S. M.
and
Dolžanskiĭ
,
F. V.
, “
Analogs of the Euler-Lagrange equations and magnetohydrodynamics connected with Lie groups
,”
Dokl. Akad. Nauk SSSR
19
,
149
153
(
1978
).
You do not currently have access to this content.