Re: matrix substitution
- To: mathgroup at smc.vnet.net
- Subject: [mg67920] Re: matrix substitution
- From: Roger Bagula <rlbagula at sbcglobal.net>
- Date: Fri, 14 Jul 2006 02:11:14 -0400 (EDT)
- References: <e665nv$n43$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
References questioned by Paul Abbott in this thread: volume 3, page 336 , Mathematics ,its content, methods and meaning,MIT press ,Mass. 1963 The Russian 2by2 matrix transform of complex numbers: a+I*b--> {{a,b},{-b,a}} 1->{{1,0},{0,1}} I->{{0,1},{-1,0}} 0->{0,0},{0,0}} The Russian Non-Euclidean transform: ( page 120 volume 3) x'=(x+a)/(1+a*x) y'=(y*Sqrt[1-a^2)/(1+a*x) Roger Bagula wrote: >In certain complex 2by2 groups there >are equivalent 4by4 representations >whicg you can get by the substitutiuon: > >1->{{1,0},{0,1}} >I->{{0,1},{-1,0}} >An example; >I used the code : > >a = {{1, 0}, {0, 1}} >b = {{0, 1}, {-1, 0}} >c = {{0, 0}, {0, 0}} >i = MatrixForm[{{c, a}, {-a, c}}] >j = MatrixForm[{{c, b}, {b, c}}] >k = MatrixForm[{{b, c}, {c, -b}}] >e = MatrixForm[{{a, c}, {c, a}}] >q[t_, x_, y_, z_] = ExpandAll[e*t + x*i + j*y + k*z] > >to get: >i = {{0, 0, 1, 0}, {0, 0, 0, 1}, {-1, 0, 0, 0}, {0, -1, 0, 0}} > >j = {{0, 0, 0, 1}, {0, 0, -1, 0}, {0, 1, 0, 0}, {-1, 0, 0, 0}} > >k = {{0, 1, 0, 0}, {-1, 0, 0, 0}, {0, 0, 0, -1}, {0, 0, 1, 0}} > >e = {{1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}} >( Try e^2-i^2-j^2-k^2) >But I got the result by hand after the fact. >There should be a way to do the derivation directly, >but my skills aren't up to it, yet. > >My current problem is quotient group made from the golden mean >characteristic: > >a=Table[x^n,{n,0,1}] >b=Table[PolynomialMod[a[[n]]*a[[m]],x^2-x-1],{n,1,2},{m,1,2}] >MatrixForm[b] > >The result is a quotient group for the golden men. >Which gives a multipilcation table like:1->e, x->I >{{e,I},{I,e+I}} >which I can do the same sort of substitution on, >but I'd like to have a more effective method! > >The benefit of the 4b4 matrices is that the result is in real numbers >without and complex numbers. > > >