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chaosbook:discrete [2009/03/19 09:03]
predrag John's remarks on visualization of R_{xz} quotiented state space
chaosbook:discrete [2010/02/02 07:55]
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-<- [[:​chaosbook]] 
  
-====== Chapter: World in a mirror ====== 
- 
-(ChaosBook.org blog, chapter [[http://​chaosbook.org/​paper.shtml#​discrete|World in a mirror]]) ​ --- //​[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2009-02-12//​ 
- 
-===== Discrete symmetry desymmetrization ===== 
- 
-==== Quotienting the discrete translation pCF symmetry ==== 
- 
-From Halcrow et al. paper on pCf equilibria: 
- 
-<​latex>​ 
-\begin{equation} 
-        \label{subg4RR} ​ 
- ​R_{xz} = \{e, \sigma_x \tau_{xz}, \sigma_z \tau_{xz}, \sigma_{xz}\} 
-        = \{e,​\sigma_{xz}\} \times \{e,​\sigma_{z}\tau_{xz}\} 
-        \simeq S \,. 
-\end{equation} 
-</​latex>​ 
- 
-The <​latex>​R_{xz}</​latex>​ isotropy subgroup is particularly important, as the  
-equilibria belong to this conjugacy class, as do 
-most of the solutions reported here. The //NBC// isotropy subgroup of 
-Schmiegel and our //S// are conjugate to <​latex>​R_{xz}</​latex>​ under 
-quarter-cell coordinate transformations. In keeping with previous literature, 
-we often represent this conjugacy class with 
-<​latex>​S = \{e, s_1, s_2, s_3\} = \{e, \sigma_z \tau_x, \sigma_x \tau_{xz}, 
-\sigma_{xz} \tau_z\}</​latex>​ rather than the simpler conjugate group <​latex>​R_{xz}</​latex>​. 
- 
-{{gtspring2009:​gibson.png?​24}} Re. methods of visualizing the state-space portraits with the  
-4th-order <​latex>​R_{xz}</​latex>​ isotropy subgroup quotiented out: the double-angle trick from Lorenz will not suffice here, since 
-we have mirror symmetry <​latex>​(x,​y,​z) \to (-x,​y,​z)</​latex>​ as well as the 
-rotation-about axis <​latex>​(x,​y,​z) \to (-x,​y,​-z)</​latex>​. The double-angle trick is 
-suitable only for the latter. It would reduce the four quadrants to 
-two, but unfortunately not in the way we would like: it would map 
-<​latex>​\tau_{xz} EQ2 to EQ2</​latex>​ and <​latex>​\tau_z EQ2 \to \tau_x EQ2</​latex>,​ leaving us with distinct 
-<​latex>​EQ2,​ \tau_x EQ2</​latex>​. And it's <​latex>​EQ2,​ \tau_x EQ2</​latex>​ we are most interested 
-in equating. -- // John F. Gibson 2009-03-19//​ 
chaosbook/discrete.txt ยท Last modified: 2010/02/02 07:55 (external edit)