A Lie algebraic generalization of the Mumford system, its symmetries and its multi-Hamiltonian structure
A Lie algebraic generalization of the Mumford system, its symmetries and its multi-Hamiltonian structure
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芒福德系统的李代数推广、其对称性及其多重哈密顿结构
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发表时间:
2007
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通讯作者:
P. Vanhaecke
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作者:
M. Pedroni;P. Vanhaecke
its symmetries and its multi-Hamiltonian structure Marco Pedroni1 and Pol Vanhaecke2;3 Abstract In this paper we generalize the Mumford system which describes for any xed g all linear ows on all hyperelliptic Jacobians of dimension g. The phase space of the Mumford system consists of triples of polynomials, subject to certain degree constraints, and is naturally seen as an a ne subspace of the loop algebra of sl(2). In our generalizations to an arbitrary simple Lie algebra g the phase space consists of dimg polynomials, again subject to certain degree constraints. This phase space and its multi-Hamiltonian structure is obtained by a Poisson reduction along a subvariety N of the loop algebra g(( 1)) of g. Since N is not a Poisson subvariety for the whole multi-Hamiltonian structure we prove an (algebraic) Poisson reduction theorem for reduction along arbitrary subvarieties of an a ne Poisson variety; this theorem is similar in spirit to the MarsdenRatiu reduction theorem. We also give a di erent perspective on the multi-Hamiltonian structure of the Mumford system (and its generalizations) by introducing a master symmetry; this master symmetry can be described on the loop algebra g(( 1)) as the derivative in the direction of and is shown to survive the Poisson reduction. When acting (as a Lie derivative) on one of the Poisson structures of the system it produces a next one, similarly when acting on one of the Hamiltonians (in involution) or their (commuting) vector elds it produces a next one. In this way we arrive at several multi-Hamiltonian hierarchies, built up by a master symmetry. Mathematics Subject Classi cation (1991): 58F07, 17B81.
DOI:
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发表时间:
2005
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影响因子:
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作者:
T. Kobayashi;T. Oshima
通讯作者:
T. Oshima