Reversing symmetry group of Gl ( 2 , Z ) and PGl ( 2 , Z ) matrices with connections to cat maps and trace maps
Reversing symmetry group of Gl ( 2 , Z ) and PGl ( 2 , Z ) matrices with connections to cat maps and trace maps
复制标题
Gl(2,Z)和PGl(2,Z)矩阵的反转对称群与猫图和跟踪图的连接
DOI:
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发表时间:
1997
期刊:
影响因子:
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通讯作者:
J. Roberts
中科院分区:
文献类型:
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作者:
M. Baake;J. Roberts
Dynamical systems can have both symmetries and time-reversing symmetries. Together these two types of symmetries form a group called the reversing symmetry group R with the symmetries forming a normal subgroup S of R. We give a complete characterization of R (and hence S) in the dynamical systems associated with the groups of integral matrices Gl(2,Z) and PGl(2,Z). To do this, we use well known methods of number theory, such as Dirichlet’s unit theorem for quadratic fields and Gauß’ results on the equivalence of integer quadratic forms, and employ the algebraic structure of the modular group PSl(2,Z) as a free product. We show how some recently discussed generalizations of the reversing symmetry group are also nicely illustrated when we consider affine extensions of these matrix groups. Our results are applicable to hyperbolic toral automorphisms (Anosov or cat maps), pseudo-Anosov maps, and the group of three-dimensional (3D) trace maps that preserve the Fricke–Vogt invariant.