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Re: Ploting a transformation of a set

  • To: mathgroup at smc.vnet.net
  • Subject: [mg123497] Re: Ploting a transformation of a set
  • From: DrMajorBob <btreat1 at austin.rr.com>
  • Date: Fri, 9 Dec 2011 05:55:18 -0500 (EST)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • References: <4EDCB5F0.813B.006A.0@newcastle.edu.au>
  • Reply-to: drmajorbob at yahoo.com

The short (or not so short) answer is:

Eigenvalues@{{-1/2*S22*\[Chi]^2 + I*a21*\[Chi],
    I/(2*\[HBar])*\[CapitalDelta], -I/(2*\[HBar])*\[CapitalDelta],
    0}, {I/(2*\[HBar])*\[CapitalDelta],
    2*S12/\[HBar] - S22*X^2/2 - 2*S11/\[HBar] - I*\[Epsilon]/\[HBar] -
     2*I*\[Lambda]/\[HBar],
    0, -I/(2*\[HBar])*\[CapitalDelta]}, \
{-I/(2*\[HBar])*\[CapitalDelta],
    0, -2*S12/\[HBar] - S22*X^2/2 - 2*S11/\[HBar] +
     I*\[Epsilon]/\[HBar] + 2*I*\[Lambda]/\[HBar],
    I/(2*\[HBar])*\[CapitalDelta]}, {0, -I/(2*\[HBar])*\[CapitalDelta],
     I/(2*\[HBar])*\[CapitalDelta], -1/2*S22*\[Chi]^2 + I*a21*\[Chi]}}

{-(1/2) \[Chi] (-2 I a21 + S22 \[Chi]),
  Root[16 S11 \[CapitalDelta]^2 +
     4 S22 X^2 \[CapitalDelta]^2 \[HBar] -
     32 I a21 S11^2 \[Chi] \[HBar] + 32 I a21 S12^2 \[Chi] \[HBar] +
     32 a21 S12 \[Epsilon] \[Chi] \[HBar] -
     8 I a21 \[Epsilon]^2 \[Chi] \[HBar] +
     64 a21 S12 \[Lambda] \[Chi] \[HBar] -
     32 I a21 \[Epsilon] \[Lambda] \[Chi] \[HBar] -
     32 I a21 \[Lambda]^2 \[Chi] \[HBar] +
     16 S11^2 S22 \[Chi]^2 \[HBar] - 16 S12^2 S22 \[Chi]^2 \[HBar] +
     16 I S12 S22 \[Epsilon] \[Chi]^2 \[HBar] +
     4 S22 \[Epsilon]^2 \[Chi]^2 \[HBar] +
     32 I S12 S22 \[Lambda] \[Chi]^2 \[HBar] +
     16 S22 \[Epsilon] \[Lambda] \[Chi]^2 \[HBar] +
     16 S22 \[Lambda]^2 \[Chi]^2 \[HBar] -
     16 I a21 S11 S22 X^2 \[Chi] \[HBar]^2 +
     8 S11 S22^2 X^2 \[Chi]^2 \[HBar]^2 -
     2 I a21 S22^2 X^4 \[Chi] \[HBar]^3 +
     S22^3 X^4 \[Chi]^2 \[HBar]^3 + 32 S11^2 \[HBar] #1 -
     32 S12^2 \[HBar] #1 + 8 \[CapitalDelta]^2 \[HBar] #1 +
     32 I S12 \[Epsilon] \[HBar] #1 + 8 \[Epsilon]^2 \[HBar] #1 +
     64 I S12 \[Lambda] \[HBar] #1 +
     32 \[Epsilon] \[Lambda] \[HBar] #1 + 32 \[Lambda]^2 \[HBar] #1 +
     16 S11 S22 X^2 \[HBar]^2 #1 - 32 I a21 S11 \[Chi] \[HBar]^2 #1 +
     16 S11 S22 \[Chi]^2 \[HBar]^2 #1 + 2 S22^2 X^4 \[HBar]^3 #1 -
     8 I a21 S22 X^2 \[Chi] \[HBar]^3 #1 +
     4 S22^2 X^2 \[Chi]^2 \[HBar]^3 #1 + 32 S11 \[HBar]^2 #1^2 +
     8 S22 X^2 \[HBar]^3 #1^2 - 8 I a21 \[Chi] \[HBar]^3 #1^2 +
     4 S22 \[Chi]^2 \[HBar]^3 #1^2 + 8 \[HBar]^3 #1^3 &, 1],
  Root[16 S11 \[CapitalDelta]^2 +
     4 S22 X^2 \[CapitalDelta]^2 \[HBar] -
     32 I a21 S11^2 \[Chi] \[HBar] + 32 I a21 S12^2 \[Chi] \[HBar] +
     32 a21 S12 \[Epsilon] \[Chi] \[HBar] -
     8 I a21 \[Epsilon]^2 \[Chi] \[HBar] +
     64 a21 S12 \[Lambda] \[Chi] \[HBar] -
     32 I a21 \[Epsilon] \[Lambda] \[Chi] \[HBar] -
     32 I a21 \[Lambda]^2 \[Chi] \[HBar] +
     16 S11^2 S22 \[Chi]^2 \[HBar] - 16 S12^2 S22 \[Chi]^2 \[HBar] +
     16 I S12 S22 \[Epsilon] \[Chi]^2 \[HBar] +
     4 S22 \[Epsilon]^2 \[Chi]^2 \[HBar] +
     32 I S12 S22 \[Lambda] \[Chi]^2 \[HBar] +
     16 S22 \[Epsilon] \[Lambda] \[Chi]^2 \[HBar] +
     16 S22 \[Lambda]^2 \[Chi]^2 \[HBar] -
     16 I a21 S11 S22 X^2 \[Chi] \[HBar]^2 +
     8 S11 S22^2 X^2 \[Chi]^2 \[HBar]^2 -
     2 I a21 S22^2 X^4 \[Chi] \[HBar]^3 +
     S22^3 X^4 \[Chi]^2 \[HBar]^3 + 32 S11^2 \[HBar] #1 -
     32 S12^2 \[HBar] #1 + 8 \[CapitalDelta]^2 \[HBar] #1 +
     32 I S12 \[Epsilon] \[HBar] #1 + 8 \[Epsilon]^2 \[HBar] #1 +
     64 I S12 \[Lambda] \[HBar] #1 +
     32 \[Epsilon] \[Lambda] \[HBar] #1 + 32 \[Lambda]^2 \[HBar] #1 +
     16 S11 S22 X^2 \[HBar]^2 #1 - 32 I a21 S11 \[Chi] \[HBar]^2 #1 +
     16 S11 S22 \[Chi]^2 \[HBar]^2 #1 + 2 S22^2 X^4 \[HBar]^3 #1 -
     8 I a21 S22 X^2 \[Chi] \[HBar]^3 #1 +
     4 S22^2 X^2 \[Chi]^2 \[HBar]^3 #1 + 32 S11 \[HBar]^2 #1^2 +
     8 S22 X^2 \[HBar]^3 #1^2 - 8 I a21 \[Chi] \[HBar]^3 #1^2 +
     4 S22 \[Chi]^2 \[HBar]^3 #1^2 + 8 \[HBar]^3 #1^3 &, 2],
  Root[16 S11 \[CapitalDelta]^2 +
     4 S22 X^2 \[CapitalDelta]^2 \[HBar] -
     32 I a21 S11^2 \[Chi] \[HBar] + 32 I a21 S12^2 \[Chi] \[HBar] +
     32 a21 S12 \[Epsilon] \[Chi] \[HBar] -
     8 I a21 \[Epsilon]^2 \[Chi] \[HBar] +
     64 a21 S12 \[Lambda] \[Chi] \[HBar] -
     32 I a21 \[Epsilon] \[Lambda] \[Chi] \[HBar] -
     32 I a21 \[Lambda]^2 \[Chi] \[HBar] +
     16 S11^2 S22 \[Chi]^2 \[HBar] - 16 S12^2 S22 \[Chi]^2 \[HBar] +
     16 I S12 S22 \[Epsilon] \[Chi]^2 \[HBar] +
     4 S22 \[Epsilon]^2 \[Chi]^2 \[HBar] +
     32 I S12 S22 \[Lambda] \[Chi]^2 \[HBar] +
     16 S22 \[Epsilon] \[Lambda] \[Chi]^2 \[HBar] +
     16 S22 \[Lambda]^2 \[Chi]^2 \[HBar] -
     16 I a21 S11 S22 X^2 \[Chi] \[HBar]^2 +
     8 S11 S22^2 X^2 \[Chi]^2 \[HBar]^2 -
     2 I a21 S22^2 X^4 \[Chi] \[HBar]^3 +
     S22^3 X^4 \[Chi]^2 \[HBar]^3 + 32 S11^2 \[HBar] #1 -
     32 S12^2 \[HBar] #1 + 8 \[CapitalDelta]^2 \[HBar] #1 +
     32 I S12 \[Epsilon] \[HBar] #1 + 8 \[Epsilon]^2 \[HBar] #1 +
     64 I S12 \[Lambda] \[HBar] #1 +
     32 \[Epsilon] \[Lambda] \[HBar] #1 + 32 \[Lambda]^2 \[HBar] #1 +
     16 S11 S22 X^2 \[HBar]^2 #1 - 32 I a21 S11 \[Chi] \[HBar]^2 #1 +
     16 S11 S22 \[Chi]^2 \[HBar]^2 #1 + 2 S22^2 X^4 \[HBar]^3 #1 -
     8 I a21 S22 X^2 \[Chi] \[HBar]^3 #1 +
     4 S22^2 X^2 \[Chi]^2 \[HBar]^3 #1 + 32 S11 \[HBar]^2 #1^2 +
     8 S22 X^2 \[HBar]^3 #1^2 - 8 I a21 \[Chi] \[HBar]^3 #1^2 +
     4 S22 \[Chi]^2 \[HBar]^3 #1^2 + 8 \[HBar]^3 #1^3 &, 3]}

Those are the roots of

d = Det@{{-1/2*S22*\[Chi]^2 + I*a21*\[Chi],
     I/(2*\[HBar])*\[CapitalDelta], -I/(2*\[HBar])*\[CapitalDelta],
     0}, {I/(2*\[HBar])*\[CapitalDelta],
     2*S12/\[HBar] - S22*X^2/2 - 2*S11/\[HBar] -
      I*\[Epsilon]/\[HBar] - 2*I*\[Lambda]/\[HBar],
     0, -I/(2*\[HBar])*\[CapitalDelta]}, {-I/(2*\[HBar])*\
\[CapitalDelta],
     0, -2*S12/\[HBar] - S22*X^2/2 - 2*S11/\[HBar] +
      I*\[Epsilon]/\[HBar] + 2*I*\[Lambda]/\[HBar],
     I/(2*\[HBar])*\[CapitalDelta]}, {0, \
-I/(2*\[HBar])*\[CapitalDelta],
     I/(2*\[HBar])*\[CapitalDelta], -1/2*S22*\[Chi]^2 +
      I*a21*\[Chi]}} // Factor

-(1/(16 \[HBar]^3))\[Chi] (2 a21 +
     I S22 \[Chi]) (16 I S11 \[CapitalDelta]^2 +
     4 I S22 X^2 \[CapitalDelta]^2 \[HBar] +
     32 a21 S11^2 \[Chi] \[HBar] - 32 a21 S12^2 \[Chi] \[HBar] +
     32 I a21 S12 \[Epsilon] \[Chi] \[HBar] +
     8 a21 \[Epsilon]^2 \[Chi] \[HBar] +
     64 I a21 S12 \[Lambda] \[Chi] \[HBar] +
     32 a21 \[Epsilon] \[Lambda] \[Chi] \[HBar] +
     32 a21 \[Lambda]^2 \[Chi] \[HBar] +
     16 I S11^2 S22 \[Chi]^2 \[HBar] -
     16 I S12^2 S22 \[Chi]^2 \[HBar] -
     16 S12 S22 \[Epsilon] \[Chi]^2 \[HBar] +
     4 I S22 \[Epsilon]^2 \[Chi]^2 \[HBar] -
     32 S12 S22 \[Lambda] \[Chi]^2 \[HBar] +
     16 I S22 \[Epsilon] \[Lambda] \[Chi]^2 \[HBar] +
     16 I S22 \[Lambda]^2 \[Chi]^2 \[HBar] +
     16 a21 S11 S22 X^2 \[Chi] \[HBar]^2 +
     8 I S11 S22^2 X^2 \[Chi]^2 \[HBar]^2 +
     2 a21 S22^2 X^4 \[Chi] \[HBar]^3 + I S22^3 X^4 \[Chi]^2 \[HBar]^3)

The SIMPLE factors give these eigenvalues:

Solve[Take[d, 4] == 0]

{{a21 -> -(1/2) I S22 \[Chi]}, {\[Chi] -> 0}}

Leaving those out of it and concentrating on REAL variables, other  
eigenvalues might come from Solve, as follows.

\[HBar]^3 doesn't factor out of the 5th factor in d:

ComplexExpand@Through[{Re, Im}@d[[5]]] // Factor

{2 \[Chi] \[HBar] (16 a21 S11^2 - 16 a21 S12^2 + 4 a21 \[Epsilon]^2 +
     16 a21 \[Epsilon] \[Lambda] + 16 a21 \[Lambda]^2 -
     8 S12 S22 \[Epsilon] \[Chi] - 16 S12 S22 \[Lambda] \[Chi] +
     8 a21 S11 S22 X^2 \[HBar] + a21 S22^2 X^4 \[HBar]^2),
  16 S11 \[CapitalDelta]^2 + 4 S22 X^2 \[CapitalDelta]^2 \[HBar] +
   32 a21 S12 \[Epsilon] \[Chi] \[HBar] +
   64 a21 S12 \[Lambda] \[Chi] \[HBar] +
   16 S11^2 S22 \[Chi]^2 \[HBar] - 16 S12^2 S22 \[Chi]^2 \[HBar] +
   4 S22 \[Epsilon]^2 \[Chi]^2 \[HBar] +
   16 S22 \[Epsilon] \[Lambda] \[Chi]^2 \[HBar] +
   16 S22 \[Lambda]^2 \[Chi]^2 \[HBar] +
   8 S11 S22^2 X^2 \[Chi]^2 \[HBar]^2 + S22^3 X^4 \[Chi]^2 \[HBar]^3}

Hence, we have to assume \[HBar] is nonzero. We can also assume \[Chi] is  
nonzero, since we already have a root corresponding to \[Chi] = 0.

vars = Variables@d

{\[Chi], a21, S22, \[HBar], S11, \[CapitalDelta], X, S12, \[Epsilon], \
\[Lambda]}

eqns = Flatten@{ComplexExpand@Through[{Re, Im}@d[[5]]] == 0 //
      Thread, \[HBar] != 0, \[Chi] != 0};
Solve[eqns]
(* long output *)

You can change that to solve for your preferred variables in terms of  
others (not the choices Solve makes for us).

Bobby

On Thu, 08 Dec 2011 04:27:52 -0600, ç?? ç«¥ <z.tong1017 at gmail.com> wrote:

> hello,can u help me solve a matrix problem~
> A1 = {{-1/2*S22*\[Chi]^2 + I*a21*\[Chi],
>    I/(2*\[HBar])*\[CapitalDelta], -I/(2*\[HBar])*\[CapitalDelta],
>    0}, {I/(2*\[HBar])*\[CapitalDelta],
>    2*S12/\[HBar] - S22*X^2/2 - 2*S11/\[HBar] -
>     I*\[Epsilon]/\[HBar] - 2*I*\[Lambda]/\[HBar],
>    0, -I/(2*\[HBar])*\[CapitalDelta]}, {-I/(2*\[HBar])*\
> \[CapitalDelta],
>    0, -2*S12/\[HBar] - S22*X^2/2 - 2*S11/\[HBar] +
>     I*\[Epsilon]/\[HBar] + 2*I*\[Lambda]/\[HBar],
>    I/(2*\[HBar])*\[CapitalDelta]}, {0, \
> -I/(2*\[HBar])*\[CapitalDelta],
>    I/(2*\[HBar])*\[CapitalDelta], -1/2*S22*\[Chi]^2 +
>     I*a21*\[Chi]}} // MatrixForm
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Solve the eigenvalues of the matrix A1,thx!~
>


-- 
DrMajorBob at yahoo.com



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